The mortality rate for people with mental illness (MI) is approximately 70% more than for the general population even after adjusting for relevant factors such as socio-economic status.1 In the case of people with severe mental illness (SMI) such as schizophrenia the rate is even higher.1 As a result, their life expectancy is between 15 and 20 years less than that of the general population, a gap similar to that of Indigenous peoples.2 The vast majority of excess deaths are because of chronic physical disease. Indeed, excess mortality from chronic physical disorders is 10 times that of suicide yet receives far less attention.1, 2

Even though the risk of mortality is greatest for those with SMI, almost three quarters of the absolute number of excess deaths occurs among people who have only ever attended primary care for psychiatric treatment.1 These preventable deaths therefore concern all clinicians, not just mental health clinicians.

Differences in mortality rates between people with MI and the rest of the population have either remained stable or worsened over the last 20–30 years.3 This is because people with a mental illness have also benefited from the access to preventative measures that have reduced the incidence of chronic disorders such as cardiovascular disease and cancer in the general population. These disorders share many of the same modifiable risk factors such as smoking, obesity and substance use.

Tobacco use is a good example given that up to 80% of people with schizophrenia smoke. Despite these high levels, smoking cessation is often not included in routine psychiatric care. For instance, barely 50% of smokers admitted to a smoke-free psychiatric unit were prescribed nicotine replacement therapy (NRT) even in the presence of nicotine withdrawal.4 On discharge, less than 1% were encouraged to stop smoking, referred for a formal cessation programme, or provided NRT.4 In another study, only 12% of psychiatric outpatients received cessation counselling compared with 38% of primary care attendees.5 This is in spite of the fact that common smoking cessation treatments such as varenicline, bupropion and nicotine replacement therapy have been shown to be effective in people with MI as well as those in the general population.6

However, lifestyle cannot be the sole explanation. A comprehensive systematic review and meta-analysis of cancer incidence previously published in this journal found that overall cancer incidence was not increased among people with schizophrenia.7 However, despite the incidence of many cancers being the same as the general population, mortality is greater.8 If lifestyle factors were the only explanation, incidence should more closely mirror the death mortality. Although there is less information for other disorders in the absence of the equivalent of cancer registers, illnesses such as cardiovascular disease share many of the similar risk factors such as smoking, substance use and obesity. If someone is not more at risk of a condition, but more likely to die of it, this is suggestive of a greater case fatality and possible issues around treatment. Other reasons could include poor cancer screening participation rates in those with MI, delays in diagnosis leading to more advanced disease at diagnosis or difficulties in access to appropriate cancer services and treatment.

In a large systematic review and meta-analysis of 47 publications on 4.7 million individuals, screening for breast, cervical, prostate and overall cancer was significantly less frequent in people with MI than the general population.9 There were similar findings on adjusted analyses for colorectal screening in SMI.10

Aside from screening, there may be other reasons for delays in diagnosis. Physical illnesses may be more difficult to detect in the context of a pre-existing psychiatric condition given the symptom overlap. Somatic complaints such as decreased energy and the loss of appetite or weight may have both a psychiatric and physical aetiology and it is possible that these symptoms may be ascribed to underlying psychiatric disorders, sometimes described as diagnostic overshadowing.

Once a cancer diagnosis is made, reduced access to appropriate curative treatment may also contribute to increases in case fatality. In a large population-based Australian study, people with a history of psychiatric illness were significantly less likely to receive surgery, especially resection of colorectal, breast and cervical cancers even after adjusting for the presence on metastases at initial presentation.8 They also received significantly less radiotherapy for breast, colorectal or uterine cancers, and fewer chemotherapy sessions.8

Although disparities in access to appropriate screening services and treatment have been well documented, there is less information on possible solutions. The paper by Fujiwara and colleagues from Japan is thus a welcome addition to the literature.11 They undertook a randomised control trial of 172 patients that assessed the effects of a manualised intervention of information on colorectal cancer screening and assistance with pathways navigation from a case manager. There was an initial consultation of approximately quarter of an hour followed by two brief follow-up sessions of less than 5 min each. The controls received treatment as usual (TAU). This included a standard health department leaflet on the five available cancer screening programmes that is distributed annually to all households. A significantly higher proportion of participants received colorectal cancer screening in the form of a faecal occult blood test (FOBT) (47.1%) than controls [11.8%]. Interestingly, the rate of lung cancer in the intervention group was also significantly higher than in the TAU group even though that was not a focus of the study. There were some limitations including a lack of information beyond the intervention year, rates of follow-up colonoscopy in participants with a positive FOBT result or the effect on colorectal cancer mortality rates. Nevertheless, the results suggest that a brief intervention that could potentially be applied elsewhere may produce a threefold increase in screening by FOBT.

What else can be done to address the issue of excess mortality from cancer and other chronic physical disorders in people with MI given the similar barriers to access and risk factors such as smoking, obesity and dyslipidaemia? One is dealing with the stigma arising from psychiatric illness both within the general society and the health profession. The second is encouraging people with MI to be linked with a general practitioner or family physician and the avoidance of diagnostic overshadowing when they do attend for care. Shared mental health care models may also help. Integrating psychiatric and primary care at a common site or increasing the role of psychiatric providers in general and preventive medical services may also be possible solutions.12 Jurisdiction-wide collaboration between specialist mental health services and primary care in the development of guidelines and toolkits have been shown to improve the monitoring of physical health in people with SMI.13 In mental health services, cardio-metabolic syndrome can be minimised through the choice of an appropriate antipsychotic medications and lifestyle interventions. For instance, the most recent clinical practice guidelines for the management of schizophrenia from the Royal Australian and New Zealand College of Psychiatrists do not recommend olanzapine as a first-line agent in new presentations of psychosis.14 Where a psychotropic medication with prominent metabolic side effects cannot be avoided, such as clozapine, co-prescription of metformin or a glucagon-like peptide should be considered.15, 16

With the level of psychiatric morbidity, the increased mortality rate in this population is a major public health concern. Given that nearly three quarters of these potentially preventable deaths occur in people who have only ever been seen in primary care for their mental health problem, this is an issue that extends well beyond mental health services. It is time reduction of physical health comorbidity was given equal priority to the prevention of suicide.

Data sharing is not applicable to this article as no new data were created or analyzed in this study.