Chunk #25 — 3. Common liability to addiction — 3.2. Mechanisms of variation in CLA — 3.2.1. Empirical support for the common addiction liability concept
al., 2009). Key support for the CLA concept comes from the high genetic correlations between liabilities to specific drug addictions (correlations between the genetic components of the liability variance) determined in biometrical genetic studies. Virtually no specific genetic variance is estimated (Kendler et al., 2003), aside from the licit/illicit groupings related to the legality of use (Kendler et al., 2007), i.e., to the behavioral response to societal norms. Non-drug-specific mechanisms, e.g., reflected in neurobiological data pertaining to drug-related reinforcement, suggest commonality of many drug effects involving dopaminergic and other major neurobiological systems, despite differences in the routes of administration, biotransformation pathways, and primary targets of psychoactive substances. Importantly, these systems substantially overlap with those that are involved in the mechanisms of behavior regulation, natural reward and incentive motivation, stress response, and social behavior (rev. in Vanyukov et al., 2003b).
