Depression and Anxiety Linked to Subsequent Risk for Thyroid Diseases

Symptoms of anxiety and depression are associated with a significantly increased risk for both hypothyroidism and hyperthyroidism, according to study results published in Depression and Anxiety.

Although there is a wealth of evidence on the effect of thyroid dysfunction on depression and anxiety, few studies evaluate how symptoms of anxiety and depression affect the subsequent development of thyroid diseases like hypothyroidism and hyperthyroidism.

Therefore, researchers conducted a cohort study using data from the UK Biobank to prospectively examine the association between depression and anxiety and the risk of developing thyroid disease. The primary exposures of interest were symptoms of depression and anxiety, measured at baseline via the self-reported Patient Health Questionnaire-4 (PHQ-4). The primary outcome of interest was a subsequent diagnosis of thyroid disease (defined as hypothyroidism, hyperthyroidism, nontoxic goiter, and thyroiditis) over a follow-up period of 1 to 13 years. Participants diagnosed with thyroid disease at baseline were excluded from the analysis, as were those with missing exposure or outcome information.

A total of 349,993 participants were included in the analysis. The participants had a mean (SD) age of 55.51 (8.08) years, body mass index (BMI) of 27.13 (4.67) kg/m², and 52.24% were women. Most participants (81.6%) had a normal PHQ score at baseline, while 14.4% were mild, 2.8% were moderate, and 1.3% were severe. Among the participants with anxiety and depression, the incidence of thyroid disorders was 2.82%.

 After adjusting for sex, age, and education, the researchers found that all levels of depression and anxiety were significantly associated with an increased risk for hypothyroidism and hyperthyroidism (all P ≤.007), with hazard ratios (HRs) ranging from 1.23 to 2.01. When the models were further adjusted to include smoking and BMI, the increased risk for hypothyroidism and hyperthyroidism remained significant (all P ≤.021).

Additionally, more severe PHQ scores were associated with increased risks for subsequent thyroid diseases. For example, men with severe anxiety and depression were 3 times as likely to develop hyperthyroidism relative to those with normal PHQ scores (HR, 3.02; 95% CI, 1.64-5.54; P <.001).

However, the researchers did not observe a significant relationship between PHQ scores and nontoxic goiter or thyroiditis in fully adjusted models.

These findings demonstrate a significant association between thyroid disease and anxiety and depression symptoms, as elevated PHQ scores increased the risk for subsequent hypothyroidism and hyperthyroidism. “Therefore, any level of depression and anxiety should be taken into consideration in thyroid disease risk prediction and prevention,” the researchers concluded.

Study limitations include the reliance on self-reported data of depression and anxiety symptoms, the lack of thyroid function data, and the inability to generalize findings outside of the United Kingdom.

This article originally appeared on Psychiatry Advisor