Background: All thyroid states are associated with psychiatric manifestation, be it hypothyroid, hyperthyroid or euthyroid state. Depression is more severe in hypothyroidism. Aims and objectives: The study was conducted to evaluate the effect of adequate antidepressant dose of escitalopram on thyroid function in patients with depression of euthyroid state over a period of six weeks and the relationship between thyroid function and depression. Material and methods: The study was conducted at Government Medical College Srinagar and associated hospitals from May 2013 to April 2016. The study sample comprised of 191 patients diagnosed with first episode depression. The evaluation of patients was done by using pro-forma to gather information on parameters pertaining to mental health/ illness also physical indices. DSM-5 diagnostic criteria have been used for diagnosing the patients having depression. Diagnosis was confirmed by the consultant in the department. Hamilton Depression Rating scale (HAM-D) has been used for assessing the severity of depression. Baseline thyroid function test was performed in these patients and these patients were given approved/adequate dose of escitalopram. Results: The mean age was 35.3 years and males were 55.5%. Only 19.9% have family history with psychiatric illness and 11.5% have family history of thyroid disorder. HAMD score before treatment was 13.34 ± 3.080 (p<0.001) and after first follow up 11.24 ± 2.742 (p<0.001) and after second follow up was 9.96 ± 2.33 (p<0.001) and TSH before treatment 3.45 ± 1.52 (p<0.001) and after first follow up 4.55 ± 1.69 (p<0.001), and after second follow up 4.53 ± 1.59 (p=0.791). The thyroid changes in first and second follow up was negligible 54.5% and 53.9% and changes within thyroid range 30.4% and 45% and changes within subclinical range was 15.2% and 1% respectively. Conclusion: It is concluded that escitalopram was not associated with clinically significant changes in thyroid function in normal thyroid function patients with depression. However, results suggest that patients with normal thyroid function, who were treated with escitalopram, are more susceptible to minor changes.