An association between depression, anxiety and thyroid function--a clinical fact or an artefact?

Area of Science:

• Endocrinology
• Psychiatry
• Epidemiology

Background:

• Thyroid dysfunction is common and can affect mood.
• The relationship between thyroid hormones and mental health, including depression and anxiety, requires further investigation.

Purpose of the Study:

• To investigate the association between thyroid dysfunction and the prevalence of depression and anxiety.
• To analyze these relationships in a large, population-based cohort.

Main Methods:

• Utilized data from the HUNT study, including 30,589 individuals aged 40-89.
• Assessed thyroid function through thyroid assays and mental health via the Hospital Anxiety and Depression Scale (HADS).
• Employed logistic regression analysis to determine associations.

Main Results:

• Biochemical hypothyroidism was associated with a significantly lower risk of depression and anxiety compared to normal thyroid function.
• Subclinical hypothyroidism and various forms of hyperthyroidism were not identified as risk factors.
• Individuals with a history of thyroid disease exhibited an increased risk for anxiety and depression, irrespective of current thyroid function.

Conclusions:

• No statistical association was found between thyroid dysfunction and the presence of depression or anxiety disorders in this large, unselected population.
• A history of thyroid disease independently increased the risk of anxiety and depression.