A national primary-care based trial is the largest ever to determine whether lifestyle therapy is as good as psychological care for improving mental and cardiometabolic outcomes for Australians with serious mental illness.

Australian Institute of Health and Welfare data show that in 2021, 19% of Australians had received a diagnosis of depression, anxiety or any other serious mental illness over their lifetime. This figure has almost doubled since 2009. In fact, mental health conditions are the most common long term illness experienced by Australian adults.

Managing a serious mental illness involves both the management of psychiatric symptoms as well as the monitoring of cardiometabolic risk. This is because people with serious mental illnesses, such as major depression, bipolar disorder, psychosis and schizophrenia, have a higher risk of developing chronic conditions like hypertension, obesity, diabetes and heart disease. This is for a range of reasons. First, the noxious effects of psychiatric medications, such as some antipsychotics, can have deleterious effects on the endocrinological, circulatory and metabolic systems and cause significant weight gain. Second, there is some evidence that people with serious mental illness are more likely to have health behaviours that contribute to cardiometabolic risk such as smoking. Third, we have shown that there is significant co-occurrence of mental disorders with cardiometabolic conditions, which is suggestive that these conditions share pathophysiology, risk factors and risk pathways.

Can treating depression mitigate the excess cardiometabolic risk of people living with serious mental illness? - Featured Image
People with serious mental illnesses have a higher risk of developing hypertension, obesity, diabetes and heart disease (helloabc/Shutterstock).

A Danish study found a direct link between psychiatric disorders and hypertensive disorder, ischaemic heart disease, venous thromboembolism, angina pectoris, and stroke that occurred independently of familiar factors and was most pronounced in the first year after diagnosis. Taken together, this excess risk results in Australians with serious mental illness more commonly dying prematurely from the aforementioned chronic conditions than other causes like suicide. There is thus an imperative to identify and treat the excess cardiometabolic risk associated with serious mental illness in a timely fashion.

Indeed, the latest iteration of the 2023 Australian guideline for assessing and managing cardiovascular disease risk, updated to replace the 2012 version, provides an opportunity for GPs to do this. In assessing and managing a patient’s cardiovascular risk using these guidelines, GPs should consider reclassifying individuals living with severe to a higher risk category — a recommendation that was made based on a moderate certainty of evidence. Therapies that can help people with serious mental illness mitigate their excess cardiometabolic risk include care coordination, exercise counselling, modifying obesogenic inpatient environments and weight loss programs (noting a recent report of a detected signal of semaglutide-associated suicidal ideation where anti-depressants or benzodiazepines were co-reported). However, less is known about the extent to which managing psychiatric symptoms of the mental illness can reduce cardiometabolic risk in the short and long term.

While it is true that some psychiatric medications confer excess cardiometabolic risk, there is evidence that when well managed, psychiatric treatments can improve cardiometabolic markers. Secondary analysis of a trial of a collaborative care model using anti-depressant medication and psychotherapy for depression found that this approach halved the risk of subsequent cardiovascular disease events compared with usual care over eight years. There is also evidence from small studies that psychological treatment of major depression improves cardiac risk markers like heart rate variability, the gains for which were more pronounced for those with greatest cardiometabolic risk.

Lifestyle therapies (such as dietary counselling that specifically target psychiatric symptoms as the primary indication) can benefit both mental health outcomes and cardiac risk markers. A trial evaluating the impact of a Mediterranean dietary program to treat symptoms of major depressive disorder (adjunctive to pharmacotherapy) substantially improved depressive symptoms over three months. Depression scores were highly correlated with erythrocyte polyunsaturated fatty acids which, importantly, have been associated with cardiovascular health. Our research in the MJA shows that dietitians are well placed to help people with serious mental illness achieve dietary change and reduce their cardiovascular risk markers like weight.

We are now conducting the largest depression treatment trial to date, which seeks to test whether an allied health-led lifestyle therapy program can achieve the same clinical outcomes as psychologist-led care for the same cost. The trial is open to Australian adults with major depression or bipolar disorder of moderate to severe severity who can participate in a seven-session, eight-week group program delivered via videoconferencing — equating to $650 of free treatment and resources. This trial will allow us to determine whether one mental health treatment is as good as the other for mental health and cardiometabolic markers and outcomes. If you have patients who may be interested and eligible, please contact harmone@deakin.edu.au or 03 5227 2380 for further information. Investing in research to develop timely, evidence-based treatment options for people with serious mental disorders that have the dual mental and cardiometabolic benefits will go some way to address the excess disease burden in this patient population and the premature mortality gap that persists.

Professor Adrienne O’Neil is a behavioural scientist at Deakin University who specialises in lifestyle medicine and rehabilitation across mental and cardiovascular disorders. She is an NHMRC Emerging Leader Fellowship (2022-26) at the Food & Mood Centre, Institute for Mental and Physical Health and Clinical Translation (IMPACT) Institute at Deakin University. 

The statements or opinions expressed in this article reflect the views of the authors and do not necessarily represent the official policy of the AMA, the MJA or InSight+ unless so stated. 

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