Relationship between childhood adversity and bipolar affective disorder: systematic review and meta-analysis

The relationship between childhood adversity and bipolar affective disorder remains unclear. To understand the size and significance of this effect through a statistical synthesis of reported research. Search terms relating to childhood adversity and bipolar disorder were entered into Medline, EMBASE, PsycINFO and Web of Science. Eligible studies included a sample diagnosed with bipolar disorder, a comparison sample and a quantitative measure of childhood adversity. In 19 eligible studies childhood adversity was 2.63 times (95% CI 2.00-3.47) more likely to have occurred in bipolar disorder compared with non-clinical controls. The effect of emotional abuse was particularly robust (OR = 4.04, 95% CI 3.12-5.22), but rates of adversity were similar to those in psychiatric controls. Childhood adversity is associated with bipolar disorder, which has implications for the treatment of this clinical group. Further prospective research could clarify temporal causality and explanatory mechanisms.