OBJECTIVES: Drug-Related Problems (DRPs) occur frequently with antidepressants leading to treatment failure and increased morbidity in the depressed patient. The study was designed to collect preliminary data related to antidepressant drug related problems and treatment failure in India. METHODS: A cross sectional observational study was carried out for a period of four months at a mental health facility in Udupi, India. All the prescriptions of the study population were screened for Drug Related Problems (DRPs) such as ADRs and DDIs by using a computerized database system. These data were assessed for the pattern of the ADRs with respect to patient demographics, nature of the reaction, outcome of the reactions, causality, severity and preventability RESULTS: A total of 120 patients were enrolled in the study and 33 of them developed 50 Drug Related Problems (DRPs), in those 24 Drug-Drug Interactions (DDIs) and 26 Adverse Drug Reactions (ADRs). The overall incidence of DRPs in the present study was 27.5%. Among the 33 patients and the significant proportions of DRPs were in female with [p<0.01] than in male. Most of the patients who had developed DRPs was in the age group of 36-55 yrs [p<0.01] followed by other age. The common ADRs observed were hyponatremia and headache. Considering outcomes, 20 (76.9%) of cases recovered from ADRs and while assessing the preventability, 20 (76.9%) of the ADRs were definitely preventable. When causality assessments were conducted, we found that that majority of ADRs were probable and were found to be mild to moderately severe. CONCLUSIONS: An ongoing drug monitoring program aimed at assessing common drug-related problems may be key in improving treatment effectiveness in patients with depression. The involvement of community pharmacists in a pilot psychiatric drug monitoring program in India assisted in the identification of common adverse drug related problems in these patients