The complexities of biological psychiatry

It is becoming clearer that mood disorders and indeed most psychiatric disorders represent not only a disturbance of brain function (as reflected by changes of mentation) but also a complex disturbance of multiple systems body wide. These then interact with psychological factors in a highly complex manner. One example of such complexity is the role of circadian systems with, as pointed out in the editorial by Murray (this issue), virtually every cell in the body containing core clock machinery. Murray explains the importance of disturbances to the circadian rhythm in mood disorders in a wonderfully clear and concise account of our current knowledge in this field. He suggests that ‘high resolution, time series measurement is fundamental to circadian science’ and that the evolution of actigraphy adds an important tool to this endeavour. He also points out that complex psychological states vary according to the circadian rhythm, illustrating one of the many interactions between psychological and biological factors in mood disorders. This editorial complements the article by Slyepchenko et al. (this issue), in which actigraphy is used to produce time series measurement. The study employs a combination of subjectively reported data alongside objective measures gleaned from actigraphy, which not only yields data on sleep and activity but also measures light exposure. Intriguingly, both subjective and objective measures reveal evidence of abnormalities in bipolar and unipolar mood disorders. Also of note is the finding that aspects of abnormality in circadian rhythm are related to general functioning.

Circadian rhythm disturbances have been shown to be linked to inflammation and cardiovascular disease (Scheer et al., 2009). Life expectancy in bipolar disorder is reduced by 8–12 years with the major factor being cardiovascular disease. Coello et al. (this issue) investigated the 30-year cardiovascular risk scores in newly diagnosed bipolar disorder (most diagnosed in the previous 2 years), finding risk scores to be 98.5% higher than in matched control subjects. Furthermore, risk was also higher among first-degree relatives of the patients with bipolar disorder. Coello et al. suggest that this argues for strategies to reduce cardiovascular risk at an early stage of the illness.

Continuing the theme of linkages and adding further complexity still – increased levels of inflammatory markers are found to be linked to cardiovascular disease and to bipolar disorder (Rosenblat and McIntyre, 2015). In an interesting case report, Chen et al. (this issue) describe a case of mania following bariatric surgery, in which the symptoms appeared to correlate with levels of the inflammatory marker C-reactive protein (CRP). They suggest that the inflammation may provide the link between the surgery the patient underwent and the episode of mania, citing a previous case report in the journal of resolution of symptoms of mania following the administration of activated charcoal in a case which also followed bariatric surgery. Of course the relationship between the gut microbiome, inflammation and mood disorder is increasingly being recognised and has been reviewed extensively recently in the journal (Morris et al., 2018).

The complexities of treatment are such that even after over 100 pages of journal text, the Royal Australian and New Zealand College of Psychiatrists (RANZCP) guidelines for the treatment of mood disorders were still unable to cover in detail the various treatments available for mood disorder. It is welcome therefore that this month’s issue includes guidelines for the practice of electroconvulsive therapy (ECT) (Weiss et al., this issue), a treatment which is often seen as being controversial (see McLaren, this issue) but which has seen significant advances in practice over the past decade. Despite there being significant debate regarding aspects of ECT technique in the past year (Loo et al., 2018; Rosenman, 2018), the authors have been able to reach a wide consensus which will likely serve as a guide for ECT practice in Australia and New Zealand. The guidelines note that they attempt to strike a ‘balance between promoting best evidence based practise and acknowledging that electroconvulsive therapy is a continually evolving practice’. Given the complexities of brain function and especially dysfunction, and the added complexity of ECT treatment, such evolution can sometimes occur only through the study of previous experiences such as those outlined in case reports. This month there are three case reports regarding ECT in very complex situations. One reports the successful use of ECT in psychotic depression with the complication of hypertrophic obstructive cardiomyopathy (Bowes et al., this issue). The authors followed the advice in the ECT guidelines (Weiss et al., this issue) to use bifrontal rather than bitemporal placement in a situation of increased cardiac risk. Another report describes successful treatment of catatonia in the context of multiple sclerosis (Harley et al., this issue), while the third by Wagner and Klugge (this issue) reports a rare possible adverse outcome of ECT, namely, psychosis which was presumed to reflect a postictal psychosis.

As ever, the Australian & New Zealand Journal of Psychiatry (ANZJP) encourages vigorous debate of controversial issues, in this case centring around the role of biological treatments in psychiatry. To this end, McLaren (this issue) criticises the views of Dharmawardene and Menkes in their reaction to the report of the United Nations Special Rapporteur on the ‘rights of everyone to the enjoyment of the highest standards of physical and mental health’. He argues that ‘the concept of a reductionist biological psychiatry is testimony to the triumph of wishful thinking over evidence’ and that his own review of ECT shows that ‘everything that the RANZCP has claimed regarding that modality is false’. No doubt this particular debate has only just begun and both Dharmawardene and Menkes and the authors of the new RANZCP ECT guidelines (Weiss et al., this issue) may wish to expand on these matters in future issues.

Finally, Malhi and Bell (this issue) raise concerns regarding the validity of the newly created diagnosis of disruptive mood dysregulation disorder (DMDD). It seems that while we are attempting to understand the complexity of the brain and mind, we are introducing unnecessary additional complexity by concocting new disorders.