Although depressive disorder is common in the general population and both depression and bipolar disorder are conditions commonly treated by general psychiatrists, relatively little has been written about them in relation to forensic psychiatry, probably because violence in mood disorders is uncommon. Suicide and attempted suicide, by contrast, are not uncommon in both depression and bipolar disorder. The lifetime prevalence of suicide in affective disorder used to be stated as 15% but is now thought to be 2%–9%. Interpretation of existing studies is difficult given the different and changing classifications used for depression and bipolar disorder and the retrospective nature of many of them. However, in the past few years there has been a resurgence of interest in the relationship between mood disorders and violent crime, as described in this chapter. Two useful review articles have been recently published on this subject.1,2
According to ICD-10 criteria, depressive disorder is characterized by depressed mood present for most of the day and almost every day, loss of interest or pleasure in activities that are normally pleasurable, and reduced energy. In addition, the following may be present: early morning wakening, diurnal variation of mood, psychomotor retardation or agitation, marked loss of appetite, weight loss, and loss of libido. When depression is severe, psychotic symptoms characterized by delusions (usually depressive, guilty, hypochondriacal, nihilistic, or persecutory) and hallucinations may be present, and
uncommonly the patient may sink into a depressive stupor. Bipolar disorder is characterized by hypomanic (elevated or irritable mood, restlessness, increased talkativeness, reduced concentration, and so forth) or manic episodes (flight of ideas, loss of social inhibitions, grandiosity, reckless behavior, and so forth accompanied by severe or complete disruption to work and social activity) often interspersed with depressive or less commonly with mixed affective states. Depressed and also manic patients often exhibit irritability and impulsivity, which potentially can lead to violence. Serotonin dysfunction is thought to be present in affective states, and there is a large research literature that supports an association with reduced impulse control, reduced emotional regulation, and social dysfunction. Impulsivity and strong emotional states are frequently associated with violent acts.