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

BACKGROUND: The relationship between childhood adversity and bipolar affective disorder remains unclear.

AIMS: To understand the size and significance of this effect through a statistical synthesis of reported research.

METHOD: 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.

RESULTS: 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.

CONCLUSIONS: 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.