Genetic etiology of the common liability to drug dependence: Evidence of common and specific mechanisms for DSM-IV dependence symptoms

Division of Behavioral Genetics, Rhode Island Hospital, United States. Rohan
Drug and alcohol dependence (Impact Factor: 3.42). 01/2012; 123 Suppl 1(Suppl 1):S24-32. DOI: 10.1016/j.drugalcdep.2011.12.015
Source: PubMed


We investigated the etiological nature of comorbid alcohol, tobacco, and cannabis DSM-IV dependence symptoms in late adolescence and young adulthood while accounting for gender differences in the magnitude of genetic and environmental influences.
Univariate and multivariate twin modeling was used to determine the heritability of each substance and the etiology of multiple drug problems in a sample of 2484 registrants of the Center for Antisocial Drug Dependence who provided data at the second wave of an ongoing longitudinal study. We report on mean and prevalence levels of whole-life DSM-IV dependence symptoms that were assessed with the Composite International Diagnostic Interview-Substance Abuse Module. Biometrical analyses were limited to age-adjusted DSM-IV dependence symptom counts from a subset of twins that reported using alcohol, tobacco, or cannabis in their lifetime.
Male and female alcohol, tobacco, and cannabis DSM-IV symptoms are indicators of a heritable unidimensional latent continuous trait. Additive genetic factors explain more than 60% of the common liability to drug dependence. A larger proportion of the variation in each substance is attributable to substance-specific genetic and environmental factors.
These data suggest that both common and substance-specific genetic and environmental factors contribute to individual differences in the levels of DSM-IV alcohol, tobacco, and cannabis dependence symptoms.

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    • "As those studies estimate , this general addiction liability is significantly heritable . This trait, resulting from all non-substance-specific factors influencing addiction risk, is likely rooted in the basic mechanisms of behavior regulation, reward, affect, stress and socialization (Vanyukov et al. 2003b, 2012; Palmer et al. 2012). As many other complex (multifactorial ) traits, individual variation in which is determined by numerous organismic and environmental factors, addiction liability is likely a continuous trait and has a normal phenotypic distribution in the population, as per the central limit theorem. "
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    • "Similarly, religious service attendance decreased the risk for both disorders, pointing to shared pathways to the development and maintenance of these disorders, as previously suggested (Lopez-Quintero et al., 2011; Palmer et al., 2012). By contrast, predictors of lifetime smoking and lifetime cannabis use M a n u s c r i p t 19 have substantial differences, possibly suggesting substance-specific risk factors for drug use initiation but common liability for drug dependence (Palmer et al., 2012). "
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