Abstract:Background: The relation between thyroid function and depression has long been recognized. Patients with thyroid disorders are more prone to develop depressive symptoms and conversely depression may be accompanied by various subtle thyroid abnormalities. Traditionally, the most commonly documented abnormalities are elevated T4 levels, low T3, elevated rT3, a blunted TSH response to TRH, positive anti thyroid antibodies, and elevated CSF TRH concentrations.Also, a number of clinical studies have suggested a therapeutic role for thyroid hormone co-medication in patients with depression who are biochemically euthyroid. Keeping this background in mind, this study was undertaken.Aims and Objectives:1) To study prevalence of thyroid dysfunction in depression.2) To study type of thyroid dysfunction associated with depression.Materials and Methods:1) 50 consecutive new patients presenting to psychiatric OPD and diagnosed as having MDD using DSM IV TR included.2) Socio-demographic data collected using specially designed semi-structured proforma.3) Montgomery Asberg Depression Rating Scale applied to assess severity of depression.4) Thyroid functions assessed by serum T3, T4, TSHlevels.5) Data thus collected was pooled and subjected to statistical analysis.Results:Thyroid dysfunction was found to be in 32 % of patients in our study, of which 26% of patients were hypothyroid and 6 % were hyperthyroid. Hypothyroidism was presentin 10% of moderate depression patients and 16% of severe depression patients. Hyperthyroidism was present in 4% of patients with mild depression and 2% of severe depression patients.