Thyroid autoimmunity and treatment response to escitalopram in major depression

Abstract

Background: There is evidence that immune alterations play an important part in the pathogenesis of major depression. Thyroid autoimmunity has been found in association with major depression in several studies. Aim: 1) to examine whether the prevalence of anti-thyroid peroxidase autoantibodies (anti-TPO) in depressive patients differs from that in healthy controls; 2) to investigate the possible relationship between thyroid autoimmunity, total T3, free T3, free T4, thyroid-stimulating hormone (TSH), clinical status and treatment outcome in depression. Method: The study group consisted of 129 outpatients (69.8% female; mean age 31.7±12.0 years) with major depressive disorder with a Montgomery–Åzsberg Depression Rating Scale total score of 22 or higher and 72 healthy controls (62.5% female; mean age 31.7±13.1 years). The patients were treated with escitalopram 10–20 mg/day for 12 weeks using open-label placebo non-controlled design. Anti-TPO, total T3, free T3, free T4 and TSH were measured before the treatment. Results: The anti-TPO was found in eight (8.9%) depressive and two (4.8%) healthy females without statistical difference between these groups. Since anti-TPO was not seen in males, all further statistical analyses were carried out in females. At the end of week 12 of the treatment, 60 female patients (66.7%) were defined as responders and 30 depressive females (33.3%) showed insufficient response to treatment. Although there were no significant differences in the measurements between responders and non-responders, the last group showed a trend for a higher prevalence of anti-TPO compared with responders. Conclusion: Thyroid autoimmunity might be a factor predicting treatment response to antidepressants in depressive patients.

• Anti-TPO
• Escitalopram
• Major depression
• Thyroid autoimmunity

Acknowledgements

This study was supported by Estonian Science Foundation (grant 6514) and the Estonian Ministry of Education and Research (SF0180125s08).

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.