Chronic pelvic pain (CPP) is defined as cyclical and non-cyclical pain, continuous or recurrent, that persists for more than six months and limits daily activities or produces functional disability [2]. It is a multifactorial condition, encompassing muscular, skeletal, myofascial, psychological and urological variables [3], that affects between 5.7% and 26.6% of people assigned female at birth [4]. It is estimated that only one-third of people affected consult a medical professional, but only around half of all treatment-seekers will receive a positive diagnosis [5]. Furthermore, while CPP can be associated with chronic pain conditions such as dysmenorrhea [6], CPP presents as idiopathic in more than half of all cases [7].

Around half of people who have CPP experience reduced mobility and need to rest or take analgesics for pain in order to perform daily activities [8]. Besides pain itself, CPP negatively affects quality of life, with over half of the women diagnosed reporting it has impacted daily activities [8]. Among the most common complaints are restrictive lethargy and fatigue, sleep problems, sexual dysfunction, and worries regarding the cause of the pain [8]. Furthermore, women with CPP show a higher incidence of psychological comorbidities such as anxiety and depression [9].

Pharmacologically, treatment usually starts as over-the-counter analgesics before diagnosis [2]. Once the patient has been diagnosed, treatment is provided depending on the characteristics of each patient's CPP with different combinations of analgesics such as opioids [2] and non-steroidal anti-inflammatory drugs (NSAIDs; [10]. Although effective for pain relief, NSAIDs can have long-term side effects, including cardiovascular and gastrointestinal complications [11]. In light of the current opioid crisis [12], opioids are more problematic, as they generate physical dependence [13] and increased all-cause mortality in older adults to almost twice as compared to those who are treated with NSAIDs [14]. However, CPP is most effectively dealt with when treatment and diagnosis are provided by a multi-speciality team including gynaecology, gastroenterology, urology, mental health and pain specialists [15]. Additionally, interventions that involve mind-body therapies are generally recommended over pharmacotherapy and surgery [15,16]. One example of such mind-body therapy is cognitive behavioural therapy (CBT) which is now recommended as an adjuvant [6] or a stand-alone intervention [17], whereby patients are guided to reframe their thoughts and modify their responses to deal with CPP.

Hypnotherapy is another mind-body therapy that has been found clinically effective for pain, chronic pain and mood disorders [[18], [19], [20]]. Although it has been suggested that hypnotherapy works through the placebo effect, more recent research has found that they are distinct phenomena [21]. Like CBT, it works on an individual's response to pain, however, unlike CBT, new ways of thinking and responding are implanted into the mind via suggestion so that new responses are automatic, not learned or effortful. Even though the mechanisms through which it works are not fully understood, brain-imaging techniques show distinct changes in neuronal activity when under hypnosis [22]. Hypnosis is characterized by a reduction in activity within the dorsal anterior cingulate cortex (dACC), as well as increased functional connectivity between the dorsolateral prefrontal cortex (DLPFC) and the insula, while connectivity between the DLPFC and the default mode network/posterior cingulate cortex (PCC) is reduced. These alterations in neural activity are responsible for the state of heightened focus, improved somatic and emotional regulation, reduced self-awareness and increased capacity to respond to suggestion that are hallmarks of hypnosis [22,23]. Meta-analyses have demonstrated hypnotherapy as effective in decreasing chronic pain [24] and being more effective than treatment as usual or CBT to reduce chronic non-headache pain [4]. The effectiveness of gut-directed hypnotherapy in particular has been well-documented [25], and results show that it is an effective course of treatment for the pain associated with irritable bowel syndrome (IBS) and functional abdominal pain (FAP; [25].

Despite general dissatisfaction with pharmacological interventions and the success of CBT as a mind-body treatment of pain, it is surprising that the role of hypnotherapy in the treatment of CPP has not been a greater focus for research in this area. This is despite the fact that existing reviews have indicated the efficacy of hypnotherapy for various types of pain, including IBS- and FAP [25], headaches [26], cancer-related pain [27], fibromyalgia [24] and other forms of persistent pain [28] including diseases which cause CPP such as interstitial cystitis (Verghese et al., 2016).

This scoping review intends to investigate the use of hypnotherapy in the treatment of chronic pelvic pain, especially in regard to perceived pain, quality of life, anxiety, depression and fatigue. We also intend to investigate the effectiveness of hypnotherapy as an intervention by performing a meta-analysis on the few randomized clinical trials that have been conducted, and complementing it with a qualitative synthesis of relevant case series studies. As such, the review is intended to highlight gaps in the current literature to inform and prioritize future research directions.