Even the most valuable pharmacogenetic markers never tell the whole story. Treatment outcomes are always the result of a complex interplay of individual, social, and stochastic factors. In psychiatry, adherence is a serious and often overlooked problem. For complex disorders, the best treatment would be one that uniquely corrects a specific molecular defect. This is being achieved for occasional patients with rare diseases, such as dopa-responsive dystonia [Bainbridge et al 2011], but remains a major challenge, especially for neuropsychiatry.
