The influence of childhood trauma on the treatment outcomes of pharmacological and/or psychological interventions for adolescents and adults with bipolar disorder was systematically reviewed.
Randomised and non-randomised studies of interventions for bipolar disorder that included an assessment of childhood trauma were eligible. MEDLINE Complete, Embase, PsycINFO, and the Cochrane Central Register of Controlled Trials were searched. Two independent reviewers completed the screening and extraction process. Two independent reviewers assessed the risk of bias in the included studies using the Cochrane Collaboration's Risk of Bias tool and the Newcastle-Ottawa Scale. Alongside a narrative synthesis, random-effects meta-analyses were performed.
Twelve studies (1175 participants) were included. The narrative review highlighted differential treatment outcomes among individuals with a history of childhood trauma. The meta-analyses suggested that childhood trauma was unrelated to treatment response (five studies, 426 participants; odds ratio 0.58, 95% CI 0.27-1.25, p = .164) but may be associated with greater improvement in global functioning (three studies, 210 participants; Hedge's g 0.65, 95% CI 0.04-1.26, p = .037).
The impact of childhood trauma on the effectiveness of specific pharmacological/psychological interventions could not be explored due to the small body of research identified.
The overall quality of the extant evidence is low, which precludes definitive comment on the role of childhood trauma in the treatment of bipolar disorder. Additional research that uses large and representative samples is required to ascertain whether a history of childhood trauma affects the treatment outcomes of interventions for individuals with bipolar disorder.