Low TSH levels tied to depression risk in women: Study

Brazil: Low levels of thyroid-stimulating hormone (TSH) is positively associated with incident depression, especially among women, finds a recent study in the journal Clinical Endocrinology. Results were found to be similar when the analysis was restricted to euthyroid patients. Also, high TSH levels were inversely associated with depression. 

The Brazilian Longitudinal Study of Adult Health (ELSA‐Brasil) by Ana C. Varella, Universidade de São Paulo (FMUSP), São Paulo, SP, Brasil, and colleagues aimed to evaluate if baseline TSH levels were associated with incident depression after four years of follow-up in a cohort of middle-aged adults.

For the purpose, the researchers evaluated TSH and free‐thyroxine (FT4) levels at baseline. Depression diagnoses were performed using the Clinical Interview Schedule ‐ Revised (CIS‐R) at baseline and after a 4‐year‐follow‐up. Mean age of the participants was 51.5 years and 51.2% were women. 

Poisson regression models (95% Confidence Intervals) were built to evaluate the association between TSH quintiles at baseline and incident depression. All analyses were stratified by sex. Models were presented crude, adjusted for age and sex; and further adjusted for education, BMI, race, smoking, alcohol consumption, kidney function, use of antidepressants/benzodiazepines, and comorbidities. 

Key findings of the study include:

"Our results showed that low TSH levels were positively associated with incident depression, particularly among women. Similar results were found when restricting the analysis to euthyroid participants. In contrast, high TSH levels were inversely associated with incident depression, also among women," wrote the authors. 

"Thyroid‐stimulating hormone levels and incident depression: results from the ELSA‐Brasil Study," is published in the journal Clinical Endocrinology.

DOI: https://onlinelibrary.wiley.com/doi/abs/10.1111/cen.14407