Psychopharmacogenetic basis of medication-induced movement disorders.

In light of the emerging evidence for genetic vulnerability to adverse drug reactions, this article attempts to elucidate the natural history of medication-induced movement disorders from a psychopharmacogenetic perspective. Studies of the risk factors, neurobiology, and pharmacogenetics are reviewed concurrently. The relevant variables associated with 10 genetically mediated movement disorders are tabulated and compared with those of medication-induced movement disorders without a clear-cut genetic basis. As a result of this integrated analysis, it is evident that there is an intimate genetic and pathophysiological link between neuropsychiatric movement disorders of diverse origins. The emergence of drug-induced movement disorders seems to reflect a spectrum of basal ganglia derangement attributable to genetic predisposition; psychotropic medications only augment the genetic vulnerability to clinical phenotypes. It is proposed that a multidimensional analysis of the interacting variables is essential for understanding the natural history of these conditions, and that the scope of psychopharmacology should be broadened to include psychopharmacogenetics for improving therapeutic objectivity and prevention research.