Birth weight and later risk of depression in a national birth cohort
Background Low birth weight increases the risk of childhood behavioural problems, but it is not clear whether poor foetal growth has a long-term influence on susceptibility to depression. Aims To examine the relation between birth weight and risk of psychological distress and depression. Method At age 16 years 5187 participants in the 1970 British Cohort Study completed the 12-item General Health Questionnaire to assess psychological distress. At age 26 years 8292 participants completed the Malaise Inventory to assess depression and provided information about a history of depression. Results Women whose birth weight was 3 kg had an increased risk of depression at age 26 years (OR=1.3; 95% CI 1.0–1.5) compared with those who weighed > 3.5 kg. Birth weight was not associated with a reported history of depression or with risk of psychological distress at age 16 years. In men there were no associations between any measurement and the full range of birth weight but, compared with men of normal birth weight, those born weighing $2.5 kg were more likely to be psychologically distressed at age 16 years (OR=l.6, 95% CI 1.1–2.5) and to report a history of depression at age 26 years (OR=l.6, 95% CI 1.1–2.3). Conclusions Impaired neurodevelopment during foetal life may increase susceptibility to depression.