Understanding how stress triggers bipolar mood swings

22 May 2012

Distressed manBy Pamela Readhead

Financial crises, experiencing a car accident or the death of a relative are events that most people would find stressful. But how do they affect people living with bipolar disorder, a devastating mental illness? Is the humiliation of finding out that a spouse is unfaithful more likely to trigger depression or mania? Why are some people with bipolar disorder more vulnerable to these stressors than others?

These are some of the questions that are being asked by researchers at the Institute of Psychiatry, King's College, London. The interdisciplinary postdoctoral fellowship, funded by the ESRC and the Medical Research Council and awarded to Dr Georgina Hosang, aims to identify the kind of events that can trigger severe mood episodes in bipolar disorder.

The research findings suggest that financial problems, marital difficulties, job loss and personal illness were often precursors to episodes of bipolar depression and mania. "These events all involve some degree of loss – of a resource, relationship or a cherished idea," explains Dr Hosang. "Relationship problems were more likely to trigger manic episodes than depression, however the death or illness of a close relative was more often related to episodes of major depression than bipolar depression."

The fellowship will also explore factors which promote resilience to stress among people with this illness. These include having good quality supporting relationships (social support), genetic factors and a positive interpretation of negative experiences (cognitive style).

The research draws on data from a large genetic study of bipolar disorder which assessed these factors, together with the incidence of childhood maltreatment and recent stressful events, using semi-structured interviews and questionnaires. The participants also provided DNA samples for analyses.

About one per cent of the adult population has a bipolar disorder. Some people have occasional episodes of depression and elation or mania, but others have frequent extreme mood swings, sometimes associated with psychotic symptoms, such as seeing or hearing things that others don't - hallucinations - requiring treatment. Understandably this debilitating illness has an adverse impact on the individual, their families and society as a whole. For instance, approximately 50 per cent of people with bipolar disorder attempt suicide at some point in their life.

Research shows that bipolar disorder runs in families, suggesting that genetic factors play a crucial role in the development of this illness. However, identifying which genes contribute to susceptibility to bipolar disorder has proved difficult.

"The effect of genes on bipolar disorder is complex. Our research shows it is important to explore the interplay between genetics and the environment in order to improve our understanding of the development of the condition," says Dr Hosang. "For example, our results show that not everyone who experiences stressful events goes on to suffer from bipolar disorder, but an individual's genetic make-up could make them more sensitive to stress and developing or exacerbating this condition."

Dr Hosang's research findings highlight the need for stressful events to be monitored among individuals suffering with this disorder. For instance, people with bipolar disorder, their families and clinicians, could be coached to spot events that might trigger an episode and devise ways of coping, using approaches such as cognitive behaviour therapy.

"Appropriate intervention at the right time could prevent individuals with bipolar disorder relapsing, so helping to improve their lives. Such interventions would mean that the need for expensive hospital treatment would also be reduced," explains Dr Hosang.

Mental Health Awareness Week runs from Monday 21 May to Sunday 27 May.