The association between lower birth weight and comorbid generalised anxiety and major depressive disorder

ObjectiveStudies testing the association between birth weight and depression or anxiety have found inconsistent results and there has been a lack of research on the possible relationship between birth weight and comorbid anxiety and depression. We tested for an association between lower birth weight and major depression, generalised anxiety and comorbid generalised anxiety and major depression.MethodData was taken from 2113 mothers and their offspring participating in the Mater University Study of Pregnancy (MUSP) birth cohort. Generalised anxiety, major depression and comorbid generalised anxiety and major depression at 21 years were tested for associations with birth weight using multinomial logistic regression.ResultsLower birth weight was found to predict comorbid generalised anxiety and major depression, but did not predict either generalised anxiety or major depression.LimitationsWe were unable to specify comorbidity by the primary disorder, or by the severity or recurrence of the depression.ConclusionPrevious associations found between birth weight and mental health may reflect a specific link between lower birth weight and comorbid generalised anxiety and major depressive disorders. As neither disorder individually was associated with lower birth weight, this may suggest that this developmental origin represents a unique risk pathway to comorbidity not shared with either discrete disorder.