The biopsychosocial model in mental health

Recent important research has highlighted the interaction between biological and psychosocial aspects of mental illness and the complexities of this (Engert et al., 2020). This complexity includes the fact that mental illness is very frequently comorbid with a wide range of physical illnesses. In this month’s ANZJP, I encourage you to consider various aspects of this complexity and to consider evidence from across the biopsychosocial spectrum.

Several papers in this issue encourage us to think broadly regarding aspects of the spectrum – from physical comorbidity at one end of a spectrum, to social cognition at the other. While it should not necessarily be the case that patients with mental illness feel uncomfortable or marginalised in general medical services, Kalucy et al. (this issue) point out long waiting times and a high rate of dropout from assessment for obstructive sleep apnoea among patients with schizophrenia. These authors have pioneered the use of a one-bed ‘sleep laboratory’ in the context of a mental health rehabilitation unit. This innovation gives an example of an approach which truly integrates the treatment and assessment of physical and mental health problems, and provides a thorough assessment of an important factor that is often overlooked in the treatment of major mental illness.

At the other end of the biopsychosocial spectrum, Rotenberg et al. (this issue) examine social cognition in bipolar disorder. Social cognition is the processing of information relating to social interaction and not surprisingly it is an extremely complex phenomenon. Various tasks have been developed to measure the aspects of this, and Rotenberg et al. examine studies which measured this in patients with bipolar disorder when euthymic. Their rigorous meta-analysis suggests that, even when euthymic, patients with bipolar disorder have significantly reduced scores on tests of social cognition compared with healthy control subjects. The finding is important theoretically and clinically. It confirms that, even when apparently not in an episode of acute mood disturbance, patients with bipolar disorder may have underlying processing difficulties which may make social interactions more difficult and which may therefore contribute to the difficulties which patients with bipolar disorder experience in social contexts (Del Mar Bonnín et al., 2019).

Exemplifying the importance of examining the biopsychosocial spectrum is the assessment of suicidal thoughts and behaviours which may arise from interactions between features at all points in this spectrum. However, the full range of risk behaviours is often not considered. The paper by Armstrong et al. (this issue) addresses other types of ‘social risk behaviours’ which it is hypothesised are more common in men with recent suicidal ideation or a history of having attempted suicide. As hypothesised, even when sociodemographic factors were taken into account in this study, behaviours such as smoking, drug use, poor diet, lack of exercise and intimate partner violence were more common. Furthermore, when depressive symptoms were taken into account, not surprisingly, fewer associations were found. The study emphasises the need to consider these other harmful behaviours when assessing men (at present there are no data on women) presenting with suicidal ideation or attempts.

Even individual drug treatments can be complex and controversial. Stimulants, with their potential for abuse and their use in attention-deficit/hyperactivity disorder (ADHD) and depression, are frequently the subject of debate (Malhi et al., 2016), often however with relatively little data to inform discussion. However, Rohde et al. (this issue) provide useful data regarding the use of stimulants in depression. In a study of Danish nationwide health registers, outcomes in the 2 years before the redemption of a stimulant prescription were compared with outcomes in the 2 years after. The 2 years before and after stopping a stimulant were also examined. Psychiatric admissions, psychiatric bed days and incidents of intentional self-harm or suicide attempts were analysed in over 4000 patients. While there were no differences in psychiatric admissions or inpatient days comparing pre- and post-stimulant prescription, methylphenidate (by far the most commonly prescribed stimulant) was associated with a 54% reduction in incidents of self-harm or suicide. There was therefore no clear evidence of a beneficial effect as measured by parameters associated with hospitalisation, which by proxy at least reflects depression outcome at the severe end of the spectrum. However, they suggest that methylphenidate may be helpful in depression with suicidal or self-harming behaviour.

Two papers this month examine very different treatments for post-traumatic stress disorder (PTSD). While there is good evidence of clinical effectiveness for eye movement desensitisation and reprocessing (EMDR), there is little knowledge of its supposed mechanisms of action. Rousseau et al. (this issue) present evidence regarding brain activation during bilateral alternating stimulation, associated with fear extinction. Bilateral alternating stimulation in this context showed a remarkably widespread brain circuitry effect, including sensory, memory and emotional networks, all of which suggests an impact in excess of what would be expected with a simple sensory signal. In contrast to EMDR, the pharmacological mechanism of action of prazosin is well characterised, and this has become a frequently used treatment for sleep disturbance in PTSD. However, there is only limited clinical trial evidence for the effectiveness of prazosin in PTSD. In a letter, Maguire and Looi (this issue) discuss this clinical trial evidence in light of a much larger clinical trial published recently and suggest that the use of prazosin in this situation be reappraised because of the negative findings in this trial.

Once again, this month, the debate on childhood mental health literacy continues. Originally, Tully et al. (2019) pointed to low levels of parental knowledge of childhood mental health disorders and of how to seek help for these, and argued for a need for a national initiative to improve mental health literacy in childhood mental health disorders. Subsequently, Samuel (2020) responded, suggesting that increasing childhood mental health literacy may not be a priority for a number of reasons including the lack of evidence-based treatments for childhood mental health disorders and a possible negative impact of labelling disorders in childhood. This month, Tully and colleagues (this issue) reply, arguing that in several key conditions such as disruptive behaviour disorders, treatment (parent training programmes) is in fact supported by good evidence. They also point to the importance of such treatment, given the established link with later mental health difficulties. The debate is enriched by Haliburn (this issue), who argues that childhood disorders can often become chronic and affect development at crucial stages if not recognised and treated early, and she further emphasises the need for a childhood mental health literacy programme. This debate will no doubt continue in the pages of the ANZJP as will others on a broad range of biopsychosocial aspects of mental health aetiology and treatment.