Childhood trauma and longitudinal clinical outcomes in bipolar affective disorder: a systematic review

OBJECTIVE: To review the literature regarding long-term effects of childhood trauma (CT) on the progression of bipolar affective disorder (BAD) in terms of affective symptomatology, depressive symptoms, hypomanic and manic symptoms, mood and activity instability, suicidality, hospitalisation, comorbidity, relapse, treatment response and remission, and functional outcomes. METHODS: The PubMed, MEDLINE, Embase, and PsycINFO databases were searched for English-language, longitudinal studies that investigated associations between CT and psychiatric outcomes in patients with BAD. Risk of bias was assessed using the Joanna Briggs Institute Critical Appraisal Checklist for Cohort Studies. RESULTS: In total, 13 studies (involving 5418 patients) were included in the analysis. All 13 studies had a low risk of bias. Those with a history of CT had more severe manic symptoms, increased functional impairment, and higher risks of relapse, suicidality, and psychiatric comorbidities. However, findings related to depressive symptoms, hospitalisation, treatment response, and functional recovery were inconclusive. A history of physical or sexual abuse was associated with increased symptom severity, mood instability, and higher relapse risk. CONCLUSION: CT remains a key determinant of BAD progression rather than just a risk factor for onset. The differential impacts of CT subtypes suggest distinct neurobiological and cognitive mechanisms, highlighting the need for personalised, trauma-informed interventions.