Aims and MethodThere are few descriptions in the literature of pharmacogenetic applications in psychiatry. We describe the relevance of pharmacogenetics to clinical psychiatry using a case-note review of the first 55 patients to have their cytochrome P450 (CYP2D6) status assessed in a general psychiatry clinic.ResultsThe distribution of genotypes for CYP2D6 was the same as in the general population. A smaller number of reported side-effects (P=0.01) and higher medication dosages (P=0.001) were significantly associated with the extensive metabolism genotype.Clinical ImplicationsThis preliminary study suggests that CYP2D6 status may have an influence on medication dosage and adverse drug events reported by patients. Recommendations for further development are suggested.