Antithyroid antibodies in depressed patients

Area of Science:

• Psychiatry
• Endocrinology
• Immunology

Background:

• Depression is a common psychiatric disorder.
• Subtle thyroid dysfunction is hypothesized to play a role in some psychiatric conditions.
• Autoimmune thyroiditis is characterized by the presence of antithyroid antibodies.

Purpose of the Study:

• To investigate the prevalence of antithyroid antibodies in psychiatric inpatients with depressive symptoms.
• To explore the potential association between autoimmune thyroiditis and depression in a clinical psychiatric population.

Main Methods:

• Assessed antithyroid (antimicrosomal and antithyroglobulin) antibodies in 45 psychiatric inpatients.
• Included patients with prominent depressive symptoms, including 28 with DSM-III major depression.
• Measured serum thyrotropin, T4, T3 uptake, and free thyroxine index in antibody-positive patients.

Main Results:

• Nine out of 45 (20%) psychiatric inpatients had detectable antithyroid antibodies.
• This prevalence is significantly higher than the 5%-10% observed in the normal population.
• Patients with antibodies had symptomless autoimmune thyroiditis with normal thyroid function tests.

Conclusions:

• The findings support a hypothesis of subtle thyroid dysfunction in psychiatric inpatients with depressive symptoms.
• Autoimmune thyroiditis may be more prevalent in this population than previously recognized.
• Further research is warranted to elucidate the relationship between thyroid autoimmunity and depression.