Childhood Stressful Life Events and Bipolar Spectrum Disorders

In a cross–sectional study, we investigated the association of reported childhood stressful life events and bipolar spectrum disorders in an undergraduate sample. Specifically, we tested the harsh environment and stress generation explanations of the childhood stress and bipolar disorder relationship. The final sample included 155 bipolar spectrum participants and 155 demographically matched normal controls. Consistent with the harsh environment hypothesis, we found that the total number of reported childhood events, and particularly events independent of one’s behavior that occurred prior to bipolar individuals’ age of onset (using the same cutoff age for their matched normal controls) were associated with bipolar versus normal control status. Also, in partial support of the harsh environment hypothesis, total number and independent events predicted an earlier onset of bipolar episodes, but inconsistent with the hypothesis, so did dependent events. In contrast to the stress generation hypothesis, a bipolar spectrum diagnosis did not predict the number of total childhood stressors, particularly events dependent on one’s behavior occurring after the bipolar individuals’ age of onset. These findings suggest that the relationship of childhood stressors and bipolarity may be best explained by a harsh environment effect.