Association of signal transduction pathway genes and their interaction with environment factors with antidepressant treatment response

We interviewed patients bi-weekly using a standardized protocol across centres, recording duration, dosage, compliance, outcome and side-effects. Severity of depressive symptoms at baseline and the time of the interview were assessed using the HAMD-17 by a trained senior psychiatrist, blind to patients’ genotype thereafter for 8 weeks. Dose increases of the same antidepressant drugs were allowed if the patient had not achieved Clinical Global Impression (CGI) change scores indicating “much improved” or “very much improved.” Concomitant psychotropic medications were not permitted, except for a low dose of a benzodiazepine anxiolytic for the alleviation of insomnia. Drug side effects were assessed with the Treatment Emergent Symptom Scale (TESS,) every two weeks and drug compliance was also monitored routinely by nursing interview. ‘Remission’ was defined as an equal to or less than 7 scores in the HAMD-17 total score after 8 weeks’ treatment . Patients requiring a change in antidepressant drug or demonstrating non-adherence were excluded from the study.