It is well established that the life expectancy of people with severe mental illness (SMI), including schizophrenia, bipolar disorder, schizoaffective disorder and major depressive disorder, is considerably shorter (up to 30 years) than those without SMI.1 This disparity is due to modifiable risk factors, an increased prevalence of physical illness and multimorbidity (the presence of two or more long-term health conditions), adverse effects of psychotropic medicines, as well as access to and utilisation of healthcare services.1–4

A recent longitudinal cohort study by Reilly and colleagues3 reported that the prevalence of comorbidity increases at a higher rate in patients with SMI when compared with those without. The most common combination in this study was diabetes with hypertension, experienced by 4.4% of patients with SMI and 3.1% in those without SMI. Patients with SMI are at significantly higher risk for cardiovascular morbidity and mortality than those without SMI.5 Inequalities exist with respect to access to interventions for primary prevention in patients with SMI, despite patients with SMI having a higher exposure to risk factors for cardiovascular disease. Patients with SMI are less likely to have regular contact with a general medical provider and receive routine physical health screening, monitoring or interventions, whether pharmacological or lifestyle, than the general population.1 2

Psychotropic medicines are the mainstay of treatment for people with SMI. While these medicines improve life expectancy and health-related quality of life in people with SMI, they are associated with significant adverse drug events (ADEs).6 The prevalence of ADEs in mental health hospitals has recently been established to range from 10.0 to 42.0 per 1000 patient days, with 13.0%–17.3% deemed avoidable.6 Adverse effects experienced by people with SMI taking psychotropic medicines include but are not limited to weight gain, metabolic syndrome, type 2 diabetes, thyroid disease, respiratory illness and cardiovascular disease. These effects are heterogeneous both between and within psychotropic drug classes. For example, second-generation antipsychotics are widely recognised to increase the risk of metabolic syndrome; some antidepressants impact on this risk through sedation and appetite stimulation, and mood stabilisers such as valproate can also increase this risk.1 An individual with SMI such as schizoaffective disorder may be exposed to some or all of these classes of medicines throughout the course of their illness, increasing their risk for physical illness and the need to monitor and actively treat these comorbidities.

Psychotropic medicines are commonly included in screening tools to identify potentially inappropriate prescribing. The recently developed Medicines Optimisation Assessment Tool by Geeson et al 7 assists hospital pharmacists to identify patients at risk of moderate or severe medication-related problems, supporting pharmacists to better prioritise and target their interventions. Four of the 15 classes of high-risk medicines identified in this tool are psychotropic medicines, including antipsychotics, antidepressants, lithium and clozapine.

Studies in Australia have shown that over 80% of people with a psychotic illness experience unpleasant side effects from their medicines, and almost one-third live with moderate to severe impairment due to side effects.8 A recent survey of user experiences of antipsychotics found that people with SMI describe taking an antipsychotic as ‘the least worst option’.9 Service user accounts suggest that service providers often focus on symptom management for SMI and pay less attention to side effects of medicines and the potential impact of these on quality of life and functioning.9

It is nonetheless accepted that non-adherence to treatment for SMI increases the risk of relapse, hospitalisation and reduces quality of life for the patient.10 A meta-analysis by Vermeulen and colleagues11 found an increased long-term mortality risk in people with schizophrenia who did not use antipsychotics compared with those who did use these medicines. Psychotropic medicines need to be optimised to ensure adequate control of symptoms of mental illness while avoiding serious complications and negative physical health outcomes as a consequence. Medicines to treat SMI should be selected based on efficacy, relative adverse effect profiles, and consideration for the individual’s medical history and risk factors for chronic illness. Furthermore, the co-prescribing of medicines that could potentially ameliorate psychotropic-related ADEs if an alternative agent is not available should be considered as part of a medicines optimisation strategy (eg, the early initiation of metformin in people who are prescribed antipsychotics and experiencing weight gain if lifestyle and dietary interventions alone are not appropriate or have proven unsuccessful).

The lack of high-quality randomised controlled trials assessing interventions to protect the physical health of multimorbid patients with SMI means that there is a reliance on expert opinion and extrapolation of evidence from trials in healthier patients. Guidance on the appropriate prescribing of psychotropic medicines for patients with SMI is provided by the recognised bodies such as the British Association for Psychopharmacology (BAP), the American Psychiatric Association and the World Federation of Societies of Biological Psychiatry in systematic reviews and consensus agreements. The publication of BAP guidance on the management of weight gain, metabolic disturbances and cardiovascular risk associated with psychosis and antipsychotic drug treatment and the National Institute for Health and Care Excellence-adapted Lester UK Positive Cardiometabolic Health Resource tool encourages clinicians to actively monitor and intervene to protect the physical health of people with SMI.12 While guidelines are welcome, there is little in the way of quick reference guidance to assist clinicians at the point of prescribing in the identification of prescribing omissions (POs) and the management of multimorbid patients with SMI. In their current format, the guidelines do not facilitate optimising the use of medicines for primary and secondary prevention of physical illness.

The concept of medicines optimisation, a person-centred approach to ensure safe and effective medicine use so that patients obtain the best possible outcomes from their medicines, applies to medication prescribed for people of all ages and all illnesses.13 The Royal Pharmaceutical Society (RPS) suggests that medicines optimisation should be guided by four main principles: (1) aim to understand the patient’s experience, (2) evidence base choice of medicines, (3) ensure medicine use is as safe as possible, and (4) make medicines optimisation part of routine practice.14 Screening tools are often incorporated into the medicines optimisation process to address principles 2 and 3 of the four medicines optimisation guiding principles. Such tools usually incorporate a list of prescribing criteria to assist clinicians in reviewing the appropriateness of medications. Published screening tools target a variety of vulnerable populations, for example, older people (eg, STOPP (Screening Tool of Older People's Prescriptions)/START (Screening Tool to Alert to Right Treatment), Beers Criteria), frail older people (STOPPFrail, Screening Tool of Older Persons Prescriptions in Frail adults with limited life expectancy), middle-aged multimorbid patients (PROMPT (PRescribing Optimally in Middle-aged People’s Treatments) and paediatrics (PIPc [Potentially Innapropriate Prescribing in Children]).15–19 These screening tools resulted in improvements in prescribing and patient outcomes once implemented. Evaluations of the use of STOPP/START in clinical practice, for example, have shown that it can reduce the occurrence of medication-related hospitalisation, healthcare resource utilisation, falls and costs.19 There is no specific emphasis in these tools for prescribing for patients with SMI, nor is there any tailored prescribing tool that targets prescribing for patients with SMI. There is, therefore, a need to develop prescribing guidance to facilitate medicines optimisation for patients with SMI.

The concept of deprescribing and identification of potentially inappropriate medicines has received much of the attention in the area with a relative lack of evidence for the application of tools to identify POs, that is, the omission of potentially beneficial medication without a valid clinical reason. START (Screening Tool to Alert doctors to the Right Treatment) is an evidence-based screening tool containing criteria to identify POs. Polypharmacy is associated with higher rates of POs. This may be a deterrent to the application of START and similar medicines optimisation tools especially considering the medical complexity and reluctance among clinicians to start new medicines in multimorbid adults with SMI.

The overall aim of a screening tool for patients with SMI would be to enhance the quality of medicines prescribed to patients with SMI, targeting principles 2 and 3 of the RPS’ guidance for medicines optimisation, to help prescribers and pharmacists ensure medicines prescribed are evidence-based and used safely. A screening tool should ensure that primary and secondary preventative medicines are considered when clinically indicated.

Medicines optimisation is a complex multifaceted intervention and screening tools are unlikely to cover all aspects. A screening tool could, however, aid clinicians in prompting consideration for potential POs and assist clinicians in overcoming barriers such as diagnostic overshadowing, the misattribution of physical symptoms to mental illness.20 A user-friendly screening tool should lead to an overall improvement in prescribing quality, prevent avoidable ADEs and medication-related hospitalisations, improve patient adherence, and satisfaction with prescribed treatment and quality of life.