51 Finally, there are genetic factors that are likely to act across different drugs used in treatment and even different diseases, to predict treatment response. These may include genes that influence anxiety and stress response such as COMT, NPY, and 5-HTTLPR, as discussed above. They may also include genes altering cognitive function, such as COMT which predicts executive cognition.54,55 One such functional polymorphism is the Met66Val polymorphism of the brain-derived neurotrophic factor gene (BDNF), which predicts hippocampal volumes and episodic memory function.56 At present, none of the genetic markers available has found application

in clinical practice. The OPRM1 Asn40Asp polymorphism presently has potential for Inhibitors,research,lifescience,medical immediate utility in both alcoholism and nicotine addiction treatment.52,57,58 Concerning methadone treatment, human genetic variation may offer Inhibitors,research,lifescience,medical an advantage to this treatment modality for

opioid addictions, many identified variants of CYP2D6, which metabolizes codeine, have been shown to alter levels of active codeine metabolites such as oxycodone and hydrocodone, potentially altering risk of codeine usage. On the other hand, CYP3A4, which metabolizes methadone, buprenorphine, Inhibitors,research,lifescience,medical and LAAM, has not been found to have functional variants to affect metabolism of these opiates.38 The role of CB1 cannabinoid receptors role in the reward system make them a treatment target for drugs of abuse such as cannabinoids, opiates, and nicotine, and recently rimonabant has been utilized, Inhibitors,research,lifescience,medical but the role of genetic variation is unknown. Since the modes of action of certain drugs used or proposed for use in treatment including acamprosate59 and topiramate60 is unknown, the pharmacogenetic gene targets are also

unclear. However, in certain instances, treatment suitability may be defined by general clinical features and the genes influencing these features. For example, serotonergic abnormalities are thought to be important in early-onset alcoholics, and ondansetron, which targets 5-HT Inhibitors,research,lifescience,medical (serotonin)3 receptors, selectively reduced craving in early onset alcoholics as Thiamine-diphosphate kinase compared with late-onset alcoholics. Finally, variation is being uncovered in genes, such as BDNF, that mediate neuronal signaling and plasticity, and functional loci such as BDNF Met66 Val may potentially be critical to long-term selleck chemical recovery. In the future, genetic tools are likely to become increasingly useful to increase specificity of diagnosis and to develop and better target treatments. Notes The author would like to thank David Goldman and the reviewers for suggestions on this manuscript.
This paper endeavors to discuss (i) the cultural history of man’s relationship with addictive drugs; and (ii) the historical roots of the science of addiction. The first part deals with addictive substances and their “normal” patterns of use across different epochs.