Early adversity triggers severe course of bipolar disorder

People with bipolar disorder who have experienced severe adversity early in life appear to be more sensitive to stress and at greater risk of bipolar recurrence and an earlier onset of bipolar disorder than other individuals, researchers report.

"Significant early adversity may be a risk factor for a more severe course of bipolar disorder and, therefore, interventions may be especially important for individuals who have experienced severe early adversity," say Kimberly Dienes (University of California at Los Angeles, USA) and colleagues.

The researchers tested the early adversity sensitization hypothesis in 58 adults with bipolar disorder, aged an average of 41.5 years. Early adversity up to the age of 13 years was assessed by structured interview and stressful life events were evaluated every 3 months over a 1-year period.

There was an average of 0.95 stressful life events during the year, and 37 patients experienced a recurrence of their bipolar symptoms.

Individuals with relatively severe early adversity, including emotional, physical, or sexual abuse, neglect, separation, and loss, were more likely to experience a recurrence of bipolar symptoms under conditions of mild stress than individuals with mild or no early adversity.

Victims of early adversity also developed bipolar disorder at a significantly younger age than those who did not experience early adversity, at an average of 18.8 years versus 28.4 years, respectively.

The researchers note, however, that this might not be significant for every type of adversity. Exploratory analyses suggested a trend for all seven types of adversity studied, but only sexual adversity and neglect were significantly associated with an earlier age at onset of bipolar disorder.

They add that their findings did not support the behavioral sensitization hypothesis, with the number of bipolar episodes found to have no effect on the association between stress and recurrence.

Dienes et al conclude in the Journal of Affective Disorders: "If childhood adversity is a trigger of earlier onset and sensitizes individuals to stress, preventing stress exposure in high-risk families, or promoting coping capabilities in such youngsters might have positive consequences on the course of illness."

J Affect Disord 2006; 95: 43-49