Introduction

In the clinical assessment and diagnosis of Attention-Deficit/Hyperactivity Disorder [ADHD] in children and teenagers, the importance of quality assurance standards cannot be overstated. ADHD is one of the most common neurodevelopmental conditions affecting children and teenagers, with a significant impact on academic, social, and emotional functioning. Prevalence rates suggest that around 5% of the children and teenagers worldwide are affected by ADHD, making it a major public health concern.1,2 However, the transdiagnostic nature of ADHD symptoms (inattentiveness, restlessness, impulsivity) are features of many conditions, creating a higher risk of diagnostic errors and consequent erroneous or ineffective interventions.3 The quality of the diagnostic assessment process is key to achieving accurate diagnosis of ADHD.

While classification systems such as the Diagnostic and Statistical Manual of Mental Disorders Text Revision DSM-5-TR4 or the International Classification of Diseases ICD-115 provide criteria for diagnosing ADHD, they offer limited guidance on the process of obtaining an accurate diagnosis.

In the United Kingdom, the National Institute of Health and Care Excellence (NICE) offers guidelines for the diagnosis and management of ADHD6,7, but these guidelines do not specify detailed procedures for clinical practice. This gap in guidance leaves practitioners without clear direction on how to conduct assessments effectively. Recognising the need for more specific guidance, the UK Adult ADHD Network (UKAAN) has developed comprehensive guidance for assessing adults with ADHD - the Adult ADHD Assessment Quality Assurance Standard (AQAS).8 This document has been welcomed, with demands from professionals and people with lived experience for similar guidance tailored to the assessment of those aged 19 or younger. Hence, we present the ADHD Assessment Quality Assurance Standard for Children and Teenagers [CAAQAS], a quality framework for ADHD assessments of individuals between the age of 5–19 (although tertiary services may see younger children at age 4), developed through a process of expert consensus.

Why Guidance on ADHD Assessment for Children and Teenagers is Necessary

The necessity for detailed guidance in assessing children and teenagers with ADHD stems from several factors. It is a guiding principle that children, teenagers, and adults need different approaches to healthcare. The presentation of physical and mental health conditions in children and teenagers may differ considerably from that in adults; often being less clear-cut and requiring input from multiple sources (eg parents/caregivers, teachers).9 A further complexity is that children and teenagers are developing in a range of different areas (eg cognitive, emotional, and social development) and they can therefore grow out of difficulties as well as into them. The unique considerations in diagnosing ADHD in children and teenagers (such as developmental differences) necessitate specific recommendations. Thus, the use of AQAS to guide ADHD assessments is inappropriate, and tailored child-centred guidance is required.

Establishing agreed quality standards for ADHD diagnostic assessments and reports in children and teenagers can reduce variability in quality and improve overall care, ensuring those with ADHD receive support and interventions at the earliest opportunity. This means that appropriate resources can be directed towards this population, preventing ineffective and cost-ineffective treatments, potential harmful side-effects from medications and non-pharmacological treatments, unnecessary costs associated with misdiagnosis, and other treatable conditions being overlooked. Misdiagnosis could also mislead caregivers and children/adolescents, increasing the likelihood of psychological distress.

CAAQAS aims to serve as a benchmark, ensuring children and teenagers receive reliable and valid diagnostic assessments, reflecting high quality in clinical practice and standards of care. The guidance will be helpful for four groups:

Clinicians: Clarification of best practice will increase clinicians’ confidence and competence in diagnostic accuracy. It will limit potential harm from inappropriate treatment and support them to resist managerial pressures to prioritise speed over quality of assessment. Commissioners of ADHD services: The guidance will provide a benchmark regarding “what good looks like”, which can guide specifications for providers and ensure realistic allocation of resources to ADHD pathways. Policy-makers: Improved accuracy in ADHD diagnoses will advance the quality of population-based data which in turn has the potential to inform health strategies and allocation of budgets. Parents/caregivers, children, and teenagers: The guidance can educate parents and caregivers about ADHD and what to expect from an assessment. An ADHD assessment that follows these guidelines will increase confidence in the accuracy of an ADHD diagnosis and the value of a proposed management plan, empowering them to advocate for their child or teenager and participate meaningfully in their care.Terminology

We are aware of the importance of clarity of language and the debates around terminology. We have used the UK NHS Digital Service Manual standards definitions of children and adolescents in this paper. These standards specify that a ‘child’ is aged between 4 and 12 years old and a ‘teenager’ is aged between 13 and 19 years old. We are also sensitive to individual preferences within autistic communities when referring to Autism Spectrum Disorder or Autism Spectrum Condition, and the use of identity versus person-first language.10 For the purposes of this paper, we will use ‘autistic individuals’ or “autism”.

Methods The UK ADHD Partnership (UKAP)

Authors of this guideline are the UKAP executive committee members and guest authors who have worked with UKAP on consensus statements in the past. In total 16 authors, recognised as having extensive experience specialising in the assessment and treatment of ADHD in children and teenagers, were invited to contribute to this consensus. They represented a multidisciplinary panel of expertise working across a range of services and disciplines. Eight authors had medical qualifications/appointments (six child and adolescent psychiatrists and one paediatrician), five had clinical psychology qualifications/appointments and eight had academic qualifications/appointments. There was also representation by a service-user and an educational/occupational specialist.

The consensus group incorporated evidence from a broad range of sources. However, this largely reflects clinical practice, terms, and legislations in the United Kingdom, which may differ in other countries.

Development of CAAQAS

CAAQAS was developed through discussion of a series of agreed assessment-related questions and themes. These discussions used the UK NICE ADHD Clinical Guideline on “recognising, diagnosing and managing ADHD in children, young people and adults”7 which CAAQAS is designed to support. An iterative process was followed through drafting and redrafting, culminating in the formulation of a set of quality standards, or consensus statements, supported by all authors.

Seven key areas were agreed by all authors for ADHD assessments of children and teenagers, as follows:

Setting the scene for the assessment ADHD. Minimum/essential standards for assessing and diagnosing ADHD. Reduced functioning or impairment required to make a diagnosis of ADHD. Common differential diagnoses and comorbidity. The information that should be included in the assessment report. The post-diagnosis discussion. The core competencies required to conduct a diagnostic assessment of ADHD.

Following email discussions about topics and content, an initial draft was circulated to authors for their review and comments, with the aim of achieving a broad consensus. Drawing on their clinical experience, each author submitted responses to the first draft; these were collated by the lead author and an amended second draft produced. Following a series of rigorous reviews of several iterations (including a video-conference), a final draft of CAAQAS was produced and authors came to an agreement by consensus, by approving the final version.

In developing this quality standard, CAAQAS identifies three levels of recommendations:

Essential: These are non-negotiable. They include existing recommendations from the NICE guidelines and the application of DSM-5-TR or ICD-11 criteria. Highly recommended: These represent what the authors believe to be a minimum standard of quality care that should be followed in most assessments. Optional: These are highly desirable but not considered essential for practice.

At the end of each section, these are presented in a summary box of quality standard guidance for each topic.

No funding was requested or provided in preparation of this paper, and none of the authors were compensated for their time in any way. This study was not pre-registered, and no primary data was collected or analysed for this paper.

Results: Outcomes of the Expert Consensus on CAAQAS

Table 1 provides an overview of the structure of the manuscript.

Table 1 Overview of Manuscript Structure

Outcome 1: Setting the Scene for the Assessment

Preparing for a clinical assessment with a child or teenager requires careful planning and consideration to optimise its success. The aim of the assessment is for clinicians to gather the information necessary to inform interventions that will support the child or teenager’s well-being and development. Thorough preparation is essential and involves several factors, including carefully reviewing background information, selecting appropriate assessment tools, creating a conducive assessment environment, building rapport with the child or teenager and caregivers and explaining what will happen, and considering cultural and developmental factors.

Preparation and Planning

Obtain and review as much background information as possible about the child or teenager. This involves a “depth and breadth” approach, drawing on both longitudinal data (such as birth and early development records) and data from multiple systems (such as physical and mental health, educational, social services). It includes information obtained from the initial referral source, pre-assessment questionnaires, medical history, developmental milestones, family dynamics, any previous assessments or interventions, and any relevant education or social information. Any complex queries or clarifications that arise from this documentation should be dealt with prior to the interview.

Aside from the obvious need to assess the presence of ADHD symptoms, comorbidities, and potential differential diagnoses and impairment, it is helpful to consider whether any additional factors may need to be assessed, such as cognitive functioning, memory and other neuropsychological functions, social-emotional development, behavioural concerns, specific learning disabilities, intellectual disabilities, or other neurodevelopmental conditions such as autism. These assessments may need to be conducted by multidisciplinary professionals as required.

Ensure that appropriate assessment tools are selected taking age, developmental level, and presenting concerns into consideration. This may include standardised tests, observational measures, behaviour rating scales, and interviews with caregivers and teachers. Ensure that the selected tools are culturally and linguistically appropriate, and guidelines about their use are carefully followed.

Of note, legally, at least in the UK, mothers automatically have parental responsibility from birth, and fathers have parental responsibility if they were married to the mother or are named on the birth certificate. Step-parents may acquire parental responsibility through a court Parental Responsibility Order, and local authorities have parental responsibility for a child who is in care. Parental responsibility confers responsibility for a child’s wellbeing up to age 18. This responsibility persists even if the parents divorce, although it may be restricted by a court. Most divorced or separated parents continue to co-parent in a harmonious and child-centred way. However, when disagreements occur, parental consent for an assessment is only required from one person with parental responsibility11 (and none, if a child or teenager is competent to give this themselves).12

In terms of disclosure of the diagnostic assessment report, anyone with parental responsibility has a right to seek access to that child’s medical records, although a child or teenager may have capacity to decide if they want the records disclosed. There is no obligation to seek permission from or inform other holders of parental responsibility of a request for access to the records. However, doing so may allow them to explain any objection they may have. If there is third party information in the report, consent should be sought regarding sharing this information before disclosure. It may be necessary to anonymise or redact third party information if consent to share it is not given.13 It is recommended that advice is sought from an indemnity provider in such circumstances.

In most circumstances, offering both parents/caregivers the opportunity to contribute to the assessment (separately or jointly) is likely to be in the best interests of the child and will maximise the chance that the ultimate diagnostic opinion will be accurate and accepted.

Setting the Scene

The clinician needs to build rapport with parents/caregivers as well as the child or teenager. This is especially important with teenagers, who will be interviewed independently. To do this effectively it is important to clarify the parameters of the assessment, including specific goals and objectives, duration, format, and break times. This should preferably be done in advance by providing a standard pre-assessment information leaflet, but it could also be specified at the start of the session. This will help to manage everyone’s expectations and ensure they are reasonable.

The clinician must consider any obstacles that could prevent the child or teenager from fully participating in the assessment, including the fact that they can struggle to sit still or to see a motive for engagement. Determining why a child or teenager might be hesitant to engage can be difficult, but stigma, oppositionality, demand avoidance, and parental conflict about the value of the assessment should be considered. It is important to reassure children and teenagers that an assessment conducted for clinical purposes is confidential and that it is not a test that results in a “pass” or a “fail”. In cases of an assessment being undertaken as part of a court report, the individual and caregivers should be informed that the diagnosis may be disclosed more widely.

If the assessment is being conducted in-person, ensure the physical space is welcoming and comfortable. It should meet the needs of more restless children and teenagers who may wish to leave their seat, walk around, sit on the floor and/or play with toys. This can be agreed at the start of the assessment. Frequent breaks must be offered, if required. Minimise distractions and create a friendly atmosphere with age-appropriate toys, games, and activities available to engage the child or teenager and facilitate rapport-building.

If the assessment (ie the interview) is being conducted online (by video)14 check that the child or teenager is in a confidential place and cannot be overheard. Explicit acceptance should be expressed about periodic moving around if needed and/or for the use of fiddle toys. Younger children should be encouraged to bring a toy, book, blanket, etc to help them feel comfortable. Frequent breaks should be offered during online assessments. The assessor should explicitly ask teenagers to refrain from playing with their phones as this may not be visible onscreen. Provide explicit permission for children, teenagers, and caregivers to ask for information to be repeated and clarified (caregivers may be neurodivergent).

When engaging directly with a child or teenager (either online or in person) take time to introduce yourself, explain the purpose of the assessment using appropriate language, and establish trust and rapport through friendly interaction and active listening. Encourage children and teenagers to ask questions and express any concerns they may have. It can be helpful to ask why they think they are being assessed and what the outcome might be (for example, is the assessment perceived to be a punishment or a “last chance” before something else happens). It is important to clarify that the assessment will discuss differences and difficulties and that this is not a reflection of their faults. Explain that the assessment will also explore their strengths (ie, emphasise that it is not just a deficit focused assessment). Importantly, set up expectations of the assessment process (eg sometimes more than one appointment may be required) and the outcome process (ie whether the diagnostic outcome will be fed back at the end of the assessment or whether this will be fed back in a separate appointment).

The well-being of the child or teenager and their relationship with their caregivers is the top priority. Therefore, if the child or teenager becomes distressed, refuses to participate and/or demands to leave, then they should not be asked to continue.

Approach of the Assessor

Due to the chronicity of ADHD and the potential need for further appointments, a positive first appointment will encourage the child or teenager to attend future appointments. Approach the assessment with empathy and warmth, demonstrating genuine interest in the individual’s and family’s well-being. The use of neuro-affirming language, together with a compassionate and non-judgmental tone, will create a safe space for everyone to express themselves.

Every child and teenager is unique and may require different strategies for engagement, so it is important to be flexible and adaptable. The clinician should tailor their communication style and assessment techniques to suit the child’s or teenager’s individual needs and preferences. Be mindful of cultural differences and developmental considerations that may influence the assessment process and interpretation. It is also important to be mindful of the heritability of ADHD and other neurodevelopmental conditions when working with parents/caregivers. It is possible that the informants may also have characteristics of ADHD and/or other neurodevelopmental or mental health conditions.

Whilst engaging child or teenager and caregivers in a friendly and open demeanour, it is essential to maintain professionalism and integrity in all interactions. Obtain informed consent from the caregivers (and where appropriate, the child or teenager) and consider confidentiality and privacy regarding assessment outcome.

Box 1: Quality Standard Guidance on Setting the Scene for the Assessment of ADHD in Children and Teenagers

1.1 Manage the expectations of the interviewees by “setting the scene” and providing an overview of the assessment process. This could be sent out in advance or be given at the beginning of the assessment [essential].

1.2 In advance of the assessment obtain and review background and other relevant information (eg pre-assessment questionnaires, school and medical reports) from multiple sources, as appropriate [essential].

1.3 If required, select appropriate validated assessment tools for administration during the assessment taking account of age and developmental level [highly recommended].

1.4 Consider obstacles to engagement, reassure confidentiality (where appropriate), allow periodic movement, minimise distractions where possible, and offer frequent breaks [essential].

1.5 Be flexible and adaptable in engagement strategies, tailor communication style and assessment techniques to the individual child’s or teenager’s needs and consider cultural and developmental differences [essential].

Outcome 2: Minimum/Essential Standards for Assessing and Diagnosing ADHD in Children and Teenagers

Presently, there are no biomarkers, cognitive, or neuroimaging tests with sufficient specificity and sensitivity to diagnose ADHD.15 This is also the case for other mental health conditions. Therefore, we are reliant on the systematic collation of information to inform our diagnostic decision. It is widely recognised that when assessing ADHD in children and teenagers, a comprehensive semi-structured diagnostic interview should be administered to explore their clinical and behavioural presentation and associated difficulties,16 along with background developmental, medical, family, and social histories, and mental state and risk assessments. The assessment should include information from educational settings and other supplementary information.

Sources of Information

The primary interviewee must have had a close relationship with the child or teenager for a considerable time (ie, from pre-school period onwards) and be familiar with their functioning in different settings. Usually, this is a parent, caregiver, or family member (in the latter case the person must be older than the child/teenager). If it is not possible to interview someone who has known the individual for a considerable amount of time (eg in the case of an adopted or looked after child or teenager), current information can be gleaned from an informant and/or historical information from alternative sources, such as school and/or social services (if possible). When working with an interpreter, it is important to specify that an accurate translation from language to language is required, not an “interpretation” which may change the meaning.

The clinical interview should include a joint discussion with the interviewee/primary carer and the child or teenager, as well as separate discussions on their own (both ensuring privacy). The separate meetings allow for the carer’s and the child or teenager’s respective perspectives to be explored without either party being concerned about upsetting each other. This approach can facilitate open discussions about difficult topics without the potential for aggravating family relationships that may already be fraught.

It is important to enquire whether both/all of the child or teenager’s parents/caregivers hold the same view that ADHD could be a possible explanation for their difficulties. If different views are held (especially if one parent/carer is strongly opposed to a possible diagnosis of ADHD) it is necessary to explore the option of speaking to both parents/caregivers (separately or together) to enable both perspectives to be fully considered. Each parent’s/caregiver’s perspectives will be based on their familiarity with the child or teenager and the contexts in which they observe them.17,18 Variation between parental/caregiver’s perceptions regarding symptoms is not uncommon, especially for inattentiveness and less externalizing symptoms.19–21

It is essential to understand whether there are any other contextual factors that may be influencing parental perspectives of difficulties or motivations for participating (or not) in the ADHD assessment process, eg perceived stigma, child residency disputes, and allegations about parenting abilities.

Consideration of all available information will be needed to inform clinical judgment regarding whether any informant discrepancies may reflect true contextual and situational differences in symptom expression or are likely to be a consequence of perceptual differences.

In most circumstances, offering both parents/caregivers the opportunity to contribute to the assessment (separately or jointly) is likely to be in the best interests of the child and will maximise the chance that the ultimate diagnostic opinion will be accurate and accepted.

It is important to observe the child or teenager’s behaviour and to assess their mental state. However, the assessor should be aware that a cross-sectional presentation in an unfamiliar setting (such as the assessment environment) may not reflect their usual behaviour. In some cases, an additional observation of the child or teenager in an educational setting may be required. A generalised protocol may be utilised, such as a functional assessment of behaviour, as there are no validated observations for use in children or teenagers with ADHD. Independent evidence should be obtained from previous and current educational settings (eg, teacher questionnaires and/or interview, school/SEN reports, examination results). Children and teenagers in secondary schools and colleges typically have several teachers, and their behaviour may vary across subjects. Therefore, reports and questionnaires should be obtained from someone with an appropriate overview (such as the school SENCo and/or personal tutor) and/or from several teachers. If the child or teenager is not in education, an alternative professional who knows them well may be available to provide relevant information.

If a child or teenager has had previous contact with mental health services, it is good practice to review clinical records, including GP letters, previous assessment and medico-legal reports. Additional reports from social services, practitioner psychologists, psychotherapists, and occupational therapists can be helpful. This can be time-consuming but essential for children and teenagers presenting with greater complexity.

The Pre-Assessment Process

Rating scales are commonly used in services to screen for ADHD symptoms (eg, 18-point ADHD symptom scales). These scales assess the frequency of symptoms, not severity. They typically consist of a list of leading questions that follow a closed-question format (ie, yes or no answers, or a Likert scale). Most are not standardised by sex and may under-represent ADHD symptoms among those with more internalised presentations. A meta-analysis conducted by Mulraney et al22 concluded “most tools have excellent overall diagnostic accuracy as indicated by the area under the curve (AUC). However, a single measure completed by a single reporter is unlikely to have sufficient sensitivity and specificity for clinical use or population screening”. For these reasons, there have been concerns about the reliability of rating scales (especially if they are being used as a triage system to exclude people from services). The consensus group agreed that rating scales are helpful for monitoring treatment, but they should not be used as diagnostic screening tools unless supplemented with qualitative information about symptoms.

If used for screening purposes, it is essential that rating scales are supplemented with qualitative information, by giving a narrative and/or specific examples of difficulties and impairment associated with ADHD symptoms. These can be completed by parents/caregivers, teachers, and self-reported by teenagers (if appropriate). Pre-assessment information can also be used to elicit background information and current concerns, which can help to shorten the length of the clinical interview. However, this should not replace a comprehensive clinical interview. In cases where there is a lengthy gap between initial screening and appointment for assessment (eg, six months or more), the pre-assessment process needs to be repeated.

It is not unusual for information about the frequency and severity of ADHD symptoms to differ between respondents. For example, the child or teenager may behave differently when they are expected to settle, focus, and learn in a noisy class environment (especially when they lack interest in the subject) compared with when they are engaged in selected activities of interest in a more unstructured home environment. However, if differences are substantial, the clinician needs to carry out a more extensive and in-depth exploration of the evidence to try and resolve the conflicting data. As discussed above, this may require obtaining more information from other caregivers (eg, the other parent who was not present at the interview or other relatives who have a substantial care giving role). If the uncertainty relates to school information provided by one teacher (eg, the SENCo), additional direct feedback can be sought from subject teachers.

One important consideration will be to identify whether specific adjustments (strategies) are being applied by parents/caregivers and/or teachers to minimise impairments and/or optimise achievement. A further consideration may be whether the child or teenager is camouflaging or masking their symptoms; they are more likely to do this at school rather than at home (eg to “fit in”, to avoid being criticised).23 However, varying presentations across different contexts should not automatically be attributed to camouflaging. This possibility should be explored with the individual to determine whether there is evidence to support this explanation.

The Clinical Interview Process

The assessment must be conducted in face-to-face format (preferably “in person”). As direct observations during the assessment are important, purely audible format should not be used. Given recent advances in technology and a shift to remote communication during COVID-19, interviews with parents/caregivers or family members can be conducted online. However, an individual’s preference for “in person” appointments should be accommodated where possible or necessary for clinical reasons. It is important to record whether the child or teenager has taken any prescribed medication on the day of the assessment which may impact on their engagement.

For video-based online assessments, the clinician should satisfy themselves that the format affords sufficient opportunity to observe the child or teenager. The clinician should be mindful of the possibility of atypical presentation in unfamiliar settings, and a lack of observable ADHD symptoms during the assessment should not automatically lead to exclusion of a diagnosis of ADHD. Additional formal “in person” observations of the child or teenager at home, in class or alternative settings (if not in education) may be required, especially when assessing younger children. The observation should include activities that have the potential to elicit the presence of ADHD symptoms.

The clinical assessment should be undertaken using a semi-structured clinical interview (such as the ADHD Child Evaluation)24 to systematically evaluate the presence or absence of each of the 18 DSM-5-TR or ICD-11 symptoms. Several symptoms must have been present by age 12 and must be pervasive and persistent (ie, they must occur across settings over time). The interview should be a systematic qualitative enquiry about the presence of symptoms using open questions, with specific examples to illustrate difficulties. It is also helpful to ask about any adjustments that have been made to manage or prevent problems. These adjustments might include compensatory strategies applied by the child or teenager or by the people around them (eg, family, school, or occupational). Sufficient information needs to be obtained for the assessor to make a clinical judgment on whether a core symptom of ADHD is present or absent; this should not rely on the sole endorsement of prescribed categories (eg yes, no, never, sometimes, often). In addition, symptoms are required to be associated with significantly reduced functioning or impairments across social, educational, and/or occupational domains compared with the average neurotypical child or teenager of the same age.

It is important to be mindful of potential sex differences; a recent meta-analysis25 comparing severity of ADHD symptoms in males and females found that rating scale data (predominantly drawn from community samples) indicated that girls present with significantly less severe hyperactivity/impulsivity symptoms than boys. In adulthood, men were rated to have significantly more severe inattention than women with no difference in the hyperactivity/impulsivity dimension. All significant differences were of small effect size. By contrast, there were no significant differences between sexes when they were assessed using clinical diagnostic interview data. Hence, rating scale data suggests that ADHD symptoms present differently in males and females, whereas there is no significant difference when they are assessed by a clinical interview which is likely to be a more comprehensive and reliable method. While there is heterogeneity between sexes and age (with hyperactivity reducing as children and teenagers get older), the assessor must identify a number of core symptoms that are “trait-like” rather than episodic, the latter reflecting change from a pre-morbid baseline (such as an episode of depression in adolescence) rather than ADHD.

Due to developmental differences in key skills, it is essential that clinicians are familiar with realistic expectations of different age and ability ranges. Symptoms may vary throughout the day, depending on the individual’s ‘level of interest in the task and the task demands. Children and teenagers may learn strategies to compensate for their ADHD symptoms, making them less salient behaviourally. When assessing individuals with suspected or diagnosed intellectual disability, clinicians must be aware that rating scales are not usually normed on this population.

A detailed physical and mental health history must be obtained, as this information will be used to evaluate whether the presenting symptoms may be better explained by another condition. This requires a good understanding of both ADHD and overlapping conditions. This will include the individual’s ‘developmental history and possible early risk factors (use of alcohol/prenatal alcohol exposure, illicit drugs during pregnancy, birth complications, premature birth, low birth weight, developmental milestones, early temperament, and experiences of childhood adverse life experiences and trauma). There may be some instances when this information is not available, such as for children and teenagers in care.

It is essential to enquire about the child or teenager’s history of existing physical health conditions that may mimic (eg, thyroid disorders, epilepsy, sleep apnea, iatrogenic effects of medications such as corticosteroids, substance misuse) or be comorbid (eg obesity, heart disease, epilepsy, or diabetes, obesity, asthma).26–28 Additionally, enquiring about any vision or hearing issues is crucial for the differential diagnosis.

Enquiries must be made regarding the child or teenager’s current mental state, mental health, intellectual functioning, learning difficulties, and neurodevelopmental conditions. The latter includes autism, tic disorders, dyslexia, dyscalculia, and dyspraxia/developmental co-ordination disorder. Clinicians should also enquire about adverse childhood events, protective factors, and symptoms of trauma (PTSD, complex PTSD). Due to the impact on education and understanding, enquiries should be made about receptive or expressive language difficulties.

The assessor should specifically enquire about the risk of harm to self or others or harm from misadventure. Topics of enquiry may include antisocial behaviour, aggression, deliberate self-harm, substance use, sexual health, and victimisation/exploitation. Risk in both physical and digital contexts should be considered. The risk assessment should document the nature of the risk, precipitating, perpetuating, and protective factors, and a risk management plan.

NICE Guidelines recommend that a baseline physical assessment should be conducted before starting medication, hence medical practitioners may include this in their diagnostic assessment. This should involve a review of physical health (including centiles to aid interpretation) including height, weight, pulse, blood pressure, and heart rate. As sensory organ deficits can impair academic and social functioning, they should enquire about hearing and visual acuity and advise parents/caregivers to discuss any suspected problems with their GP and/or optician.

Continuous Performance and Qb Testing

To date, no guidelines have recommended continuous performance tests (CPTs) (including the Qb Test, which combines a CPT with a motion track system) to be an essential component of the assessment process. A meta-analysis of studies of commercially available CPT concluded:

At the clinical level, CPTs as a stand-alone tool have only a modest to moderate ability to differentiate ADHD from non-ADHD samples. Hence, they should be used only within a more comprehensive diagnostic process.29

Regarding more specifically the Qb Test, a meta-analysis30 concluded that

When used on their own, Qb Test scores available to clinicians are not sufficiently accurate in discriminating between ADHD and non-ADHD clinical cases. Therefore, the Qb Test should not be used as stand-alone screening or diagnostic tool, or as a triage system for accepting individuals on the waiting-list for clinical services. However, when used as an adjunct to support a full clinical assessment, QbTest can produce efficiencies in the assessment pathway and reduce the time to diagnosis.

Of note, there is no evidence for the Qb Test or other devices to be used as a tool to monitor treatment response.

The literature on other neuropsychological tests, delivered mainly via digital technologies, has recently been comprehensively reviewed by NICE. With the exception of the QbTest, which is indicated as an option to support the diagnostic process in children, other tests (ie, EFSim Test, EFSim Test Web Version, Nesplora Attention Adults Aquarium, Nesplora Attention Kids Aula, QbCheck), as well as the QbTest in individuals aged 18 years and over are not endorsed by NICE in the diagnostic process for ADHD due to insufficient evidence.31

Box 2: Quality Standard Guidance on Minimum/Essential Standards for Assessing and Diagnosing ADHD in Children and Teenagers

2.1 There are many pre-assessment (baseline) rating scales that focus on the individual’s presenting problems and it is for the clinician to decide which they prefer. Rating scales are helpful for monitoring treatment, but they should not be used as diagnostic screening tools unless supplemented with qualitative information about symptoms [highly recommended].

2.2 Pre-assessment questionnaires that ask for qualitative information and provide specific examples of difficulties associated with core ADHD symptoms are helpful and can reduce the time required for the interview, eg the ADHD Child Evaluation v.2 self and informant questionnaires24 [highly recommended].

2.3 If there is a lengthy gap (ie 6 months or more) between initial screening and the assessment, the pre-assessment process should be repeated [highly recommended].

2.4 Validated questionnaires for co-morbidities are helpful to screen for other mental and physical health disorders [optional].

2.5 The clinical interview must be conducted in face-to-face format (preferably “in person”). Given recent advances in technology and a shift to remote communication during COVID-19, interviews with parents/caregivers or family members can be conducted online. However, an individual’s preference for an “in person” appointment should be accommodated where possible or necessary for clinical reasons [highly recommended].

2.6 Medical practitioners must include a baseline physical assessment for diagnostic purposes and before starting medication. This should include measures of height, weight, pulse, blood pressure, heart rate. The physical examination should be carried out in person [essential].

2.7 Information gathering: all relevant information obtained during the assessment needs to be noted in detail and includes specific examples [essential].

2.8 Where there is missing information or conflicting data between informants, this should be explored. This may reflect adjustments being made in the home and/or school setting to minimise presenting problems, differing thresholds for concern among informants, or differing attitudes of informants towards the value of diagnostic labels. Divorced or separated parents/caregivers can give different accounts and discrepancies need to be understood [highly recommended].

2.9 A systematic evaluation must be undertaken of each ADHD symptom and additional diagnostic criteria using a comprehensive and systematic approach. If a symptom is identified as occurring “often”, it is essential to elicit and document clear examples of this, along with and any adjustments being made (by the individual, family, and/or school) to avoid or prevent difficulties [essential].

2.10 Consider the degree of impairment associated with each symptom present and evaluate this against what would be expected of a typically developing young person of the same age [essential].

2.11 Assessment must employ a semi-structured clinical interview eg the ADHD Child Evaluation [ACE];24 Young-DIVA;32 K-SADS-PL33; MINI34. Alternatively, an experienced ADHD assessor may follow an interview style that follows diagnostic criteria, ensuring that all 18 symptoms, impairments, and additional criteria are fully explored. Leading questions must not be used [essential].

2.12 Assess ADHD specific developmental history and early risk factors. There may be some instances when this information is not fully available, such as for children or teenagers in care [essential].

2.13 By clinical enquiry or direct observation, consider other possible neurodevelopmental conditions and learning difficulties. Document concern and consider further investigation [essential].

2.14 Assess education and social history: academic progress, exclusions/expulsions, behaviour in class, peer group relationships, antisocial behaviour, personal relationships [essential].

2.15 Assess current mental state together the individual’s mental health history to identify common mental health problems/disorders (both current and previous), particularly those that can mimic ADHD, or are commonly comorbid with ADHD (eg anxiety, depression, obsessional compulsive disorder, conduct disorder, eating disorder, attachment disorder, substance use, self-harm) [essential].

2.16 Assess physical health history to identify any history of existing medical conditions (eg heart disease, diabetes, epilepsy, head injury) and common comorbidities such as obesity, asthma, hypermobility. Ask directly about sleep, vision, or hearing issues. Enquire about current and past medications and medication allergies [essential].

2.17 Assess risk, including risk of harm to self, to others, from others and/or harm from misadventure. Enquire about adverse childhood events, protective factors, and symptoms of trauma [essential].

2.18 Triangulate different perspectives: gather information from two or more sources (parents/caregivers, collateral information from educational, healthcare and/or social services reports, clinical and/or school observation) [essential].

2.19 The clinician must document whether or not they observed ADHD symptoms and/or other features (eg depressed affect, anxiety, tics) during the assessment whilst being mindful that symptoms may be less apparent in an atypical situation. Notably, the lack of observable ADHD symptoms during the assessment should not automatically lead to an exclusion of a diagnosis of ADHD [essential].

2.20 Additional formal “in person” observations’ of the child or teenager at home, in class or alternative settings (if not in education) may be required, especially when assessing younger children. The observation should include activities that have the potential to elicit the presence of ADHD symptoms [optional].

2.21 Continuous performance tests should not be used as stand-alone screening or diagnostic tools, or as a triage system for accepting individuals on the waiting-list for clinical services. They may be helpful when used as an adjunct to support a full clinical assessment [optional].

Outcome 3: Reduced Functioning or Impairment Required to Make a Diagnosis of ADHD

Symptoms of ADHD can interfere with or reduce the quality of the child or teenager’s academic, social, and/or occupational functioning, highlighting the importance of early intervention and support to address unique needs and challenges.35 Hence, diagnosing ADHD is not solely a matter of assessing the presence of ADHD symptoms; their severity and impact on daily functioning must be considered.

ICD-11 specifies that symptoms must be sufficiently severe that they have a direct negative impact on academic, occupational, or social functioning, referred to as “impairment” in DSM-5-TR. How to establish “impairment”, however, is not clearly defined. It can be helpful to consider whether some form of intervention is warranted. NICE Guidelines6,7 suggest that impairment from symptoms of ADHD should be at least of moderate severity and fall across at least two domains or settings based on interview and/or direct observation. The Weiss Functional Impairment Rating Scale – Parent Report or the Vineland-3 are helpful tools to support this assessment.36,37

ADHD symptoms exist on a spectrum within the broader population, with many individuals displaying some degree of these traits. Therefore, this is not a “one-size-fits-all” process. Children and teenagers with ADHD can present with a wide range of symptoms and levels of impairment, manifesting in various ways across multiple areas of life, including school behaviour and academic performance; extra-curricular, leisure and social activities; family and peer relationships; risk-taking behaviours (often associated with emotional and behavioural dysregulation), daily tasks, and psychological functioning (eg self-image and self-esteem). Clinicians should be mindful that the child or teenager’s experiences may be influenced by various factors, including individual differences, co-occurring conditions, and environmental factors.

It is crucial not to dismiss the possibility of ADHD solely based on high achievements in specific areas, such as academic success or “islands of excellence”. Some might label such individuals to have intellectual strengths, sometimes referred to as a “high-functioning” with ADHD, but this term can overlook significant challenges and burdens they face in other domains. Despite apparent success, the child or teenager may still be underperforming compared to their potential, with other areas of impairment being overshadowed by an islet of achievement. These could include struggles with social interactions, disruptions in family life, sleep disturbances, emotional dysregulation, or internalising symptoms such as a lack of confidence, low self-esteem, and heightened stress levels. Furthermore, the area of achievement may require the individual to exert substantial effort to sustain attention, suppress hyperactivity, and regulate their impulsivity leading to performance being maintained in one domain of life at the cost of fatigue, decompensation, and/or accentuation of symptoms in other domains. In turn, this may also lead to secondary mental and physical health challenges.

Family accommodations can inadvertently mask impairment in the functioning of children and teenagers with ADHD in several ways:

Compensatory Strategies: Families may develop compensatory strategies to help the individual cope with their ADHD symptoms. These strategies could include providing constant reminders, structuring routines, or simplifying tasks. While these accommodations can temporarily alleviate some difficulties, they may also obscure the true extent of the child or teenager’s impairment by artificially smoothing over challenges. Overcompensation: In efforts to support the individual, families might overcompensate by taking on responsibilities that the child or teenager would otherwise be learning to manage independently. For instance, parents/caregivers might excessively monitor homework completion or organise their belongings. This overinvolvement can mask the child or teenager’s struggles and delay their development of essential skills for independent functioning. Normalisation of symptoms: Over time, families may become accustomed to the child or teenager’s ADHD symptoms and adjust their expectations accordingly. Behaviours that would typically be seen as problematic or indicative of impairment may be perceived as normal within the family context. This normalization can lead to a lack of recognition of the individual’s ongoing difficulties in other settings, such as school or social environments. Other family members may also have ADHD, rendering the child or teenager’s challenges normative within the family, which may lead to underreporting during assessment.

Overall, while family accommodations and adjustments are often well intentioned and can provide valuable support for a child or teenager with ADHD, they can also inadvertently obscure the true extent of impairment, making it challenging to accurately assess and address the individual’s needs.

Socio-cultural norms and environmental factors can also mask ADHD. For example, hyperactivity and impulsivity may be channelled through culturally normative activity (eg, a very active outdoor or rural lifestyle, hyperactive-led practical task responsibilities; impulsive-led antisocial behaviour, or nomadic lifestyle). In such instances, family may not report any “unexpected” levels of impairments or consider the individual to be more impaired than their peers, and the assessor may need to focus on how symptoms manifested earlier in childhood when the child or teenager was not embarking on such normative activities (eg during sedentary periods or periods of solitude). In the modern age, much of childhood and adolescence is being lived “digitally” and academic, social, and emotional functioning (including impairments) may play out through digital activity. Therefore, it is important to explore proxies of hyperactivity, impulsivity, and inattention or attention regulation challenges within digital spaces.

Box 3: Quality Standard Guidance on Ascertaining Reduced Functioning or Impairment in Children and Teenagers with ADHD

3.1 The interviewer should obtain specific examples of how core ADHD symptoms have interfered with or reduced the quality of the individual’s functioning across psychological, social, academic, and/or occupational functioning. This should include the exploration of digital activity [essential].

3.2 Impairment should be of at least moderate severity and in at least two domains or settings. It can be helpful to consider the following areas: school behaviour and academic performance; extra-curricular, leisure and social activities; family and peer relationships; risk taking behaviours (often associated with emotional and behavioural dysregulation), daily tasks, and psychological functioning (eg self-image and self-esteem) [essential].

3.3 When assessing impairment, be mindful that high achievements in specific areas and/or family support and accommodations may obscure impairments. Compensation by the individual, as well as socio-cultural and environmental norms that channel ADHD symptoms, may also mask impairments [highly recommended].

Outcome 4: Common Differential Diagnoses and Comorbidity

When assessing for possible ADHD, it is essential to consider other disorders which may “mimic” ADHD. These disorders may provide a better explanation for the child or teenager’s presentation than ADHD. (For a list of the range of conditions that can mimic ADHD symptoms of inattention, hyperactivity, and impulsivity see38).

Complexity can arise because these same disorders can also co-occur with ADHD and need to be identified and managed alongside ADHD. Early identification and intervention for comorbid conditions can help mitigate their impact on developmental trajectories and improve overall outcomes for individuals with ADHD. A comprehensive approach (which may require multi-disciplinary input) that accurately assesses for ADHD and comorbidities is essential. Conditions that must be considered within an ADHD assessment in children and teenagers include:

Disruptive behaviour and dissocial disorders: Most commonly seen in males, children, and teenagers with ADHD often exhibit Oppositional defiant behaviours and/or Conduct-dissocial disorder. These conditions involve persistent patterns of disobedience, hostility, and aggression toward authority figures or peers. Anxiety Disorders: Worry, fear, distractibility, and restlessness can be symptoms of anxiety, but may be misattributed to ADHD and/or exacerbated by inappropriate stimulant treatment. Therefore, anxiety-related disorders (including Obsessive-compulsive disorder and Post-traumatic stress disorder) need to be considered as possible differential diagnoses as well as common comorbidities. Trauma: Early trauma can impact children and teenager’s development and presentations including their capacity to attend and engage. Trauma associated anxiety, hypervigilance, and the presence of fight/flight responses can mimic restlessness and impulsivity. Mood Disorders: Depression and (to a lesser extent) bipolar disorder may present as a persistent sadness, irritability, mood swings, and changes in energy levels, further impacting emotional well-being and functioning. They may also be associated with difficulty concentrating, impulsive behaviour, and excessive reward seeking. However, mood disorders are typically episodic compared to ADHD. Developmental Language Disorders: This is a condition where children and teenagers have long-term challenges talking and/or understanding words. They may have lots of ideas but find it hard to put their ideas into words and understand what other people say to them. Receptive processing problems can produce inattention. Learning Difficulties: Individuals with ADHD often struggle with academic performance and may have specific learning difficulties, such as dyslexia or dyscalculia. These can exacerbate the challenges associated with ADHD and require targeted interventions to address them. Those who have a significant discrepancy in their verbal-performance intellectual abilities (where verbal skills are superior to performance skills) are sometimes thought to have ADHD as they appear to be presenting with inexplicable academic underperformance (eg, bright and chatty in class but poor on written work). Intellectual Disability: A more generalised intellectual disability characterised by a Full Scale IQ of 70 and under plus adaptive skills difficulties can present alongside or mimic ADHD. Weak Cognitive Executive Function: Working memory and executive functioning problems (eg “scratchpad memory”, defining goals, setting priorities, task planning, initiation, evaluating progress, self-organisation, and time management) can exist independently of (and mimic) ADHD, especially in children and teenagers with brain injury or autism. Sleep Disorders: Poor quality sleep can cause inattentiveness, irritability, and restlessness and should be considered as a possible differential diagnosis. However, sleep problems, such as insomnia, restless leg syndrome, or sleep-disordered breathing, are commonly reported in individuals with ADHD. Disrupted sleep patterns can exacerbate ADHD symptoms and impair cognitive functioning, attention, and behaviour during the day. Substance Use Disorders: Teenagers with ADHD are at increased risk of developing substance use disorders,39 including alcohol and substance abuse. Impulsivity, risk-taking behaviour, and difficulties with self-regulation contribute to this heightened risk. Substance use can also mask ADHD symptoms, and withdrawal symptoms can be mistaken for ADHD symptoms. Therefore, it is inadvisable to conduct an assessment with a young person who is thought to be under the influence of substances or withdrawing from substances. The interplay between substance use and ADHD symptoms is important to consider during assessment. For example, some forms of substance use may appear to temporarily improve cognitive functioning and reduce agitation, masking the ADHD challenges and making the intoxication less apparent. Substance use in the long-term can impact cognitive functioning and hence exacerbate ADHD symptoms. Foetal Alcohol Spectrum Disorder: FASD remains the single most common aetiological cause of damage to the developing foetus.40 This is especially true in populations such as those in care.41 The complex interplay between the prenatal lifestyle of parents, especially the mother, pregnancy-related impact on the developing brain and body, alongside the postnatal traumas experienced, all increase the predisposition to ADHD. The profile, however, is not typical of other cases of ADHD. An inattentive/impulsive subtype is more common, with associated cognitive and communicatory challenges. Identifying the condition, both in terms of diagnosis and delimiting complexity of presentation, and also changes to management approaches, it is important to consider this common aetiological factor as explaining the variability in profile and medication response.42 Autism: Social communication challenges associated with autism, as well as pre-occupying interests and sensory sensitivities, can give rise to impairments or differences in interaction, motivation, focusing and learning, and/or trigger agitation. Sensory-motor features of autism may also lead to repetitive or stimulation-seeking motor behaviours. These can all accentuate the attentional regulation and hyperactivity/restlessness symptoms of ADHD and/or be mistaken for ADHD. Social and sensory challenges associated with autism can also contribute to behavioural difficulties and affect the individual’s ability to regulate their emotions and behaviours. Autistic children and teenagers may find some environments intensely anxiety-provoking and exhausting and may engage in externalising behaviours in order to release tension that feels unbearable, or else to engineer removal from the distressing environment. Children and teenagers with comorbid ADHD and autism often present with substantially greater complexity, with autism and ADHD each accentuating the impairments of the other. Inversely, autism and ADHD may also reciprocally mask one another, for example, by creating a need for novelty interspersed with a need for predictability/sameness, and by creating intense sustained focus on some detailed tasks interspersed with difficulty paying attention to other tasks. Abilities generated by each condition may also be used to mask the impairments generated by the other (eg, ADHD-related social impulsivity may over-ride autism-related anxiety in social situations; an autism-related need to adhere to rules may lead an individual to exert sufficient effort to overcome inattention and suppress hyperactivity associated with ADHD). Finally, ADHD may interact with autism to manifest in a hybrid way. For example, the impulsivity and novelty-seeking of ADHD could manifest within the realm of intense interests related to autism, resulting in risky and stimulation-seeking perseverative interests. The co-existence of autism and ADHD often necessitates comprehensive assessments and interventions tailored to the unique strengths and support needs brought about by the interaction and the reciprocal impact of the two neurodevelopmental conditions.

While modern influences like gaming and social media offer opportunities for learning and socialization, they also pose risks to children and teenager’s cognitive, social, and emotional development due to their pervasive nature and immersive characteristics. They can affect cognitive development, socialisation, emotional regulation, sleep patterns, and influence risk-taking behaviour.

While some comorbidities may be common across both age groups, there are differences in comorbidity patterns between young children and teenagers with ADHD. In younger children, common comorbidities include autism, developmental language disorder, oppositional defiant disorder (ODD), conduct-dissocial disorder (CDD), intellectual disabilities and other specific learning difficulties, sensory processing difficulties, anxiety disorders, and sleep disturbances.

As children with ADHD transition into adolescence, the pattern of comorbidities may shift. The assessor should be mindful that children and teenagers are still developing which means they can grow in and out of problems. Teenagers may or may not continue to struggle with oppositional behaviour and conduct problems. However, the nature and severity of these challenges may evolve as they navigate the demands of adolescence, including peer relationships, academic expectations, and increasing independence. Mood disorders may emerge or become more pronounced during this developmental stage. Hormonal changes generated by puberty may also interact with ADHD symptoms and self-regul