Genetic factors are believed to play a major role in the variation of treatment response and the incidence of adverse effects to medication. The aim of pharmacogenetics is to elucidate this variability according to hereditary differences. Considering current hypotheses for the mechanisms of action of antidepressants, most investigations to date have concentrated on mutations in genes coding either for the pathways in the serotonergic and noradrenergic systems or for drug-metabolizing enzymes. Recent studies shifted the emphasis on the main mechanism of drug action from changes in neurotransmitter concentration or receptor function toward long-lasting adaptive processes within the neurons. Although the results are controversial, many studies support the hypothesis that psychopharmacogenetics will help predict an individual's drug response, while minimizing the side effects. The inclusion of functional genomics, which investigates the complex gene and/or protein expression in response to a given drug, may lead to the development of novel and safer drugs.
Drug Metabolizing Enzymes As a Causal Factor in the Inter-pecies Differences in Drug Action
