Nature, nurture and mental disorder: old concepts in the new millennium

Abstract

BackgroundEvidence from twin and adoption studies has highlighted the importance of gene-environment interaction in the aetiology of mental disorders, and advances in molecular genetics have raised hopes of more rapid progress in this field of investigation.AimsTo review epidemiological knowledge concerning genetic and environmental risk factors for a cross-section of psychiatric conditions, and evidence of interaction between the two types.MethodSearches of the literature in genetic and psychiatric epidemiology, including contributions to this supplement.ResultsOverall, firm knowledge on both genetic and environmental causal factors is still fragmentary, although progress has varied among diagnostic categories. Environmental aspects have been dealt with only perfunctorily in most genetic epidemiological research.ConclusionsBetter definition and classification of environmental hazards, and closer inter-disciplinary cooperation, will be necessary in future. Specific gene-environment interaction effects seem likely to prove most important in neuropsychiatric syndromes, and a less specific genetic influence on susceptibility to environmental stress among the common mental disorders.