Introduction:Homocysteine(Hcy) has gained recognition as a marker of atherosclerosis and resulting vascular disease. Its role in psychiatric disorders has not been explored much.

Aims & Objectives: The present study was planned to assess the serum homocysteine levels in patients suffering from depression and schizophrenia and to explore the association of increased homocysteine levels with these psychiatric disorders.

Material & Method:  Fifty patients diagnosed for depression and schizophrenia based on International Classification of diseases (ICD–10) were enrolled for the study. Fifty age and sex matched healthy individuals constituted the control group. Serum homocysteine levels were estimated for all enrolled subjects. Results obtained were compared statistically among the diseased and healthy control subjects.

Result:  Mean serum homocysteine levels were significantly higher in the depression (P = 0.000) and schizophrenia (P = 0.003) patients. Further, a significant number of depression patients (42%) and schizophrenia patients were observed to have hyperhomocysteinemia.

Conclusion: Elevated Hcy concentration can be the underlying cause of psychiatric manifestations either directly or secondary to other biochemical derangements.The study suggests a strong association of hyperhomocysteinemia with psychiatric disorders specially depression. Screening of patients with depression or schizophrenia is therefore, strongly recommended.