Metabolic and Endocrine Correlates of Subclinical Hypothyroidism in Young Adults with First-Episode and Drug-Naive Major Depressive Disorder.

Background: Major Depressive Disorder (MDD) is often associated with Subclinical Hypothyroidism (SCH), but the clinical and biochemical characteristics in young, first-episode, drug-naive patients remain unclear. This study aims to examine the prevalence and clinical correlates of SCH in this population to enhance screening and management strategies.

Method: A cross-sectional study included 917 young Chinese patients (aged 18-35) diagnosed with first-episode, drug-naive MDD. Comprehensive clinical assessments were conducted, involving demographic data, psychiatric evaluations using the Hamilton Depression Rating Scale (HAMD), Hamilton Anxiety Rating Scale (HAMA), and Positive and Negative Syndrome Scale (PANSS), alongside biochemical measurements such as thyroid stimulating hormone, thyroid peroxidase antibodies (TPOAb), fasting blood glucose (FBG), total cholesterol (TC), high-density lipoprotein cholesterol (HDLC), low-density lipoprotein cholesterol (LDLC), systolic blood pressure (SBP), and diastolic blood pressure (DBP). Binary logistic regression identified clinical correlates of SCH.

Results: The prevalence of SCH among the study population was 58%. Logistic regression analysis identified significant predictors of SCH, including higher HAMD scores (OR = 1.26), TPOAb (OR = 1.003), FBG (OR = 2.28), TC (OR = 1.66), SBP (OR = 1.11), and DBP (OR = 1.07). In contrast, lower HDLC levels (OR = 0.28) were inversely associated with SCH.

Conclusion: The high prevalence of SCH in young, first-episode, drug-naive MDD patients emphasizes the need for comprehensive metabolic and endocrine evaluations. Regular monitoring of thyroid function, glucose levels, blood pressure, and lipid profiles is crucial for early detection and intervention, potentially improving clinical outcomes in this vulnerable group.