A few genetic tests to optimize medical treatments in psychiatry, either by enhancing therapeutic efficacy or reducing adverse effects, are already in place. The FDA has added genetic testing to the prescription of carbamazepine in the treatment of bipolar disorder and neuropathic pain, as variation in the human leukocyte antigen gene (HLA-B*1502) has been associated with a potentially fatal skin reaction (reviewed in (53)). The FDA also approved the first diagnostic pharmacogenetic test in 2005. The AmpliChip CYP450 Genotyping Platform assesses variants in CYP2D6 and CYP2C19, the enzymes that metabolize numerous drugs including antidepressants, antipsychotics and opiates, and is intended to help physicians prescribe the type and dosage of medications based on an individual’s genotype (53). The next step is to determine whether pharmacogenetic testing can improve treatment outcomes for drug dependence in prospective studies, and to determine whether such procedures are cost-effective compared to standard care. Such economic analyses have already been performed for smoking cessation treatments, and suggest that genetic testing can be beneficial under certain assumptions (54, 55). These include the allele frequency of the genetic variant
