CRIS blog: Investigating the impact of antipsychotic medications used to treat people with serious mental illness

Richard Hayes is a Senior Lecturer at King’s College London’s Department of Psychological Medicine.  He leads a team of researchers who use the Clinical Record Interactive Search (CRIS) database (an anonymised mental health care database) to investigate the impact of medications used on mental health care on people’s mental and physical health, particularly focusing on antipsychotics prescribed to people with serious mental illness.

Serious mental illnesses, including schizophrenia, schizoaffective disorder and bipolar affective disorder are debilitating mental disorders which have a substantial impact on people’s lives. People with serious mental illnesses live with marked health disparities, resulting from stigma, adverse lifestyles as well as the direct consequences of their mental illness. 

Our research has estimated that individuals with serious mental illnesses die between 10-15 years earlier than the general population,  comparable to the impact of  smoking, diabetes and obesity. Underlying factors however remain unclear. The higher mortality risk is only partially explained by suicide, accidents or violence, and natural causes remain an important component including death from coronary heart disease and stroke, which are in turn not fully explained by poor lifestyle choices such as smoking.

Despite improving healthcare, serious mental illnesses continue to have a chronic relapsing course and marked impairment in a high proportion of those diagnosed with these disorders.  Antipsychotic medications have been a mainstay of treatment for serious mental illnesses since the 1950s and are used to manage psychotic symptoms, including hallucinations and delusions. The effectiveness of antipsychotics currently used clinically has been assessed in numerous randomized controlled trials, however, a number of adverse effects have been reported, including, weight gain, diabetes, cardiovascular diseases, lowered white blood cell count (agranulocytosis).

Although randomized controlled trials are recognized as essential for investigating whether medications are effective, these trials are usually conducted under idealized circumstances, they tend to look at in restricted groups of people and monitor them over relatively short periods of time. In practice, antipsychotics are used in a variety of ways that are not within the scope of most randomized controlled trials. For example, prescribing more than one antipsychotic at the same time occurs. Moreover, clinicians may switch medications or increase the dose in pursuit of an optimal therapeutic effect.

Clozapine is unique among antipsychotics in having proven efficacy in individuals who have been unresponsive to other treatments. However, for a variety of reasons, psychiatrists may delay treatment with clozapine. Consequently, additional information is needed to understand fully the consequences of antipsychotic medications (desired and undesired) as they are currently used in real clinical settings.

Detailed electronic patient records provide an ideal source of data to investigate real world risks and benefits of prescribing practices. The South London and Maudsley NHS Foundation Trust (SLaM) provides comprehensive secondary mental healthcare to a population of approximately 1.2 million residents in four London boroughs (Lambeth, Southwark, Lewisham and Croydon). The Clinical Record Interactive Search (CRIS) system makes it possible for researchers to search and retrieve anonymised clinical records efficiently with over 250,000 cases represented in the CRIS system.

We are also able to link CRIS to general hospital data and cause of death data to provide information about physical health in mental health care service users. We are currently using CRIS to investigate the ways in which antipsychotics are used in clinical practice; what are the circumstances under which clinicians prescribe particular antipsychotics (or combinations of antipsychotics) and the impact that these prescribing practices have on the mental and physical health of service users.

Richard Hayes is funded by a Medical Research Council (MRC) Population Health Scientist Fellowship. The Clinical Records Interactive Search (CRIS) system is funded and developed by the National Institute for Health Research (NIHR) Mental Health Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King’s College London and a joint infrastructure grant from Guy’s and St Thomas’ Charity and the Maudsley Charity.