Subclinical thyroid dysfunction and psychiatric disorders: cross-sectional results from the Brazilian Study of Adult Health (ELSA-Brasil).

OBJECTIVE

To evaluate the association between subclinical thyroid dysfunction and psychiatric disorders using baseline data from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

DESIGN

Cross-sectional study.

PATIENTS

The study included 12 437 participants from the ELSA-Brasil with normal thyroid function (92·8%), 193 (1·4%) with subclinical hyperthyroidism and 784 (5·8%) with subclinical hypothyroidism, totalling 13 414 participants (50·6% of women).

MEASUREMENTS

The mental health diagnoses of participants were assessed by trained raters using the Clinical Interview Schedule - Revised (CIS-R) and grouped according to the International Classification of Diseases 10 (ICD-10). Thyroid dysfunction was assessed using TSH and FT4 as well as routine use of thyroid hormones or antithyroid medications. Logistic models were presented using psychiatric disorders as the dependent variable and subclinical thyroid disorders as the independent variable. All logistic models were corrected for multiple comparisons using Bonferroni correction.

RESULTS

After multivariate adjustment for possible confounders, we found a direct association between subclinical hyperthyroidism and panic disorder odds ratio [OR], 2·55; 95% confidence Interval (95% CI), 1·09-5·94; and an inverse association between subclinical hypothyroidism and generalized anxiety disorder (OR, 0·75; 95% CI, 0·59-0·96). However, both lost significance after correction for multiple comparisons.

CONCLUSION

Subclinical hyperthyroidism was positively associated with panic disorder and negatively associated with anxiety disorder, although not significant after adjustment for multiple comparisons.