Thyroid dysfunction is associated with mental health disorders along with physical manifestations of the disease. While an overactive thyroid gland has been linked to anxiety, restlessness, nervousness, the underactive thyroid gland has been shown to be associated with depression and anxiety. Mood swings are frequent. Dysregulation of the hypothalamic-pituitary-thyroid axis has been recently shown to be associated with suicidal behavior in patients with depression.

Preliminary findings presented at the recently concluded 34th European College of Neuropsychopharmacology (ECNP) Congress provide further evidence supporting the association between thyroid hormones and mental health. The new research suggests that patients with comorbid anxiety and mood disorders who have low thyroid-stimulating hormone (TSH) levels may be at increased risk for suicidal ideation.¹

The cross-sectional study included 77 patients with comorbid anxiety and mood disorders attending a stress disorders clinic. These patients were aged 18 to 73 years. Patients were tasked with completing Mini International Neuropsychiatric Interview, the Patient Health Questionnaire-9 (PHQ-9), and the General Anxiety Disorder-7 (GAD-7) scale. Fasting free thyroxine (FT4), free triiodothyronine (FT3), and TSH levels were measured.

Forty-two participants were found to have suicidal ideation. “Suicidal ideation was associated with higher scores on the PHQ-9 (15.5 vs 13.3) and with lower TSH levels (1.54 IU/L vs 2.04 IU/L)”.

A significant association was noted between serum TSH levels and suicidal ideation after adjusting “for age, gender, PHQ-9 and GAD-7 scores, education, body mass index, smoking, and use of antidepressants, tranquilizers, mood stabilizers and neuroleptics”. Participants with suicidal ideation were 54% less likely to have higher TSH compared to those who did not have suicidal ideation (odds ratio 0.46). No association was observed between suicidal ideation and serum FT4 and FT3 levels.

Based on these findings, the researchers concluded that measurement of thyroid hormones, TSH in particular, may help identify individuals with anxiety and mood disorders who are likely to have suicidal thoughts and assess risk of suicide in them.

Reference

1. Liam Davenport. Lower thyroid hormone levels a red flag for elevated suicide risk? - Medscape - Oct 12, 2021.