Hyperthyroidism and suicide: a retrospective cohort study in Sweden

Area of Science:

• Endocrinology
• Psychiatry
• Public Health

Background:

• Hyperthyroidism treatment can cause mental symptoms and impair quality of life.
• Previous research suggests a potential link between thyroid disorders and mental health outcomes.

Purpose of the Study:

• To investigate if a history of hyperthyroidism increases the risk of suicide.
• To provide data on the mental health impact of hyperthyroidism treatment.

Main Methods:

• A historic cohort study involving 43,633 patients treated for hyperthyroidism (radioiodine or surgery) between 1950-2005.
• Comparison with two control cohorts: patients with atoxic nodular goitre and patients who underwent cholecystectomy.
• Follow-up via population and health registers to ascertain suicide deaths.

Main Results:

• A naive comparison with the general Swedish population showed a moderately increased standardized mortality ratio (SMR) for suicide.
• Stratification revealed this excess risk was primarily associated with women from Stockholm.
• Direct comparison between hyperthyroid patients and control cohorts, after adjustments, showed a relative risk of suicide of 0.93 (95% CI 0.68-1.26).

Conclusions:

• The study did not confirm an elevated risk of suicide among individuals treated for hyperthyroidism.
• The findings suggest that hyperthyroidism treatment itself is not a significant risk factor for suicide.