Association of Thyroid Function with Suicidal Behavior: A Systematic Review and Meta-Analysis.

Area of Science:

• Endocrinology and Psychiatry
• Neuroendocrinology
• Metabolic and Molecular Medicine

Background:

• Thyroid disease is prevalent and impacts cognitive and mental health.
• Thyroid dysfunction is linked to neuropsychiatric conditions, but its association with suicide remains debated.
• Understanding thyroid function in suicidal behavior is crucial for mental health research.

Purpose of the Study:

• To systematically review and meta-analyze the association between thyroid function and suicidal behavior in adults.
• To compare thyroid hormone levels in individuals with and without suicidal behavior.
• To identify gaps in the current literature regarding thyroid disorders and suicide.

Main Methods:

• Systematic review and meta-analysis of four databases (MEDLINE, EMBASE, PsycINFO, Scopus) up to July 2018.
• Inclusion of 13 studies with 2807 participants (826 with suicidal behavior) reporting thyroid hormone levels.
• Random-effects models used to compare mean differences in thyroid function tests (TSH, FT4, FT3, TT4, TT3).

Main Results:

• Patients with suicidal behavior showed significantly lower mean levels of free triiodothyronine (FT3) and total thyroxine (TT4) compared to controls.
• No significant differences were found in Thyroid-stimulating hormone (TSH), free thyroxine (FT4), or total triiodothyronine (TT3) levels between groups.
• Limited studies compared overt/subclinical thyroid disease prevalence; included studies had a low-to-moderate risk of bias.

Conclusions:

• Individuals exhibiting suicidal behavior have demonstrably lower mean FT3 and TT4 levels.
• The clinical significance and underlying pathophysiologic mechanisms of these thyroid hormone differences are currently unknown.
• Further research is imperative to elucidate the relationship between thyroid function and suicidal behavior.