Why this message is appearing and what you can do to make your experience on this site better.Select Journal or Resource JAMA & Archives Home JAMA Archives of Dermatology Facial Plastic Surgery Family Medicine (1992-2000) General Psychiatry Internal Medicine Neurology Ophthalmology OtolaryngologyHead & Neck Surgery Pediatrics Eric Schmitt, BS; Steven H.PhD; Carol A.PhD _Arch Gen Psychiatry. CONTEXT While both environmental and genetic factors are important in the etiology of psychoactive substance use (PSU), we know little of how these influences differ through development.OBJECTIVE To clarify the changing role of genes and environment in PSU from early adolescence through middle adulthood.DESIGN Retrospective assessment by life history calendar, with univariate and bivariate structural modeling.SETTING Generalmunity.PARTICIPANTS A total of 1796 members of male-male pairs from the Virginia Adult Twin Study of Psychiatric and Substance Use Disorders.MAIN OUE MEASURES Levels of use of alcohol, caffeine, cannabis, and nicotine recorded for every year of the respondent's life.RESULTS For nicotine, alcohol, and cannabis, familial environmental factors were critical in influencing use in early adolescence and gradually declined in importance through young adulthood.Factors, by contrast, had little or no influence on PSU in early adolescence and gradually increased in their effect with increasing age.Sources of individual differences in caffeine use changed much more modestly over time.Correlations were seen among levels of cannabis, nicotine, and alcohol use and specifically between caffeine and nicotine.Adolescence, those correlations were strongly influenced by shared effects from the familial environment.Individuals aged, more and more of the correlation in PSU resulted from genetic factors that influenced use of both substances.CONCLUSIONS These results support an etiologic model for individual differences in PSU in which initiation and early patterns of use are strongly influenced by social and familial environmental factors while later levels of use are strongly influenced by genetic factors.Substantial correlations seen in levels of PSU across substances are largely the result of social environmental factors in adolescence, with genetic factors bing progressively more important through early and middle adulthood.AFFILIATIONS: Departments of Human Genetics (Dr Kendler and Mr Schmitt) and Psychiatry (Drs Kendler and Aggen), Virginia Institute for Psychiatric and Behavioral Genetics, Medical School of Virginia/Virginiamonwealth University, Richmond; and Department of Psychology, University of Southern California, Los Angeles (Dr Prescott).Read more Ibuprofen no better at reducing alzheimer's risk
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