Prevalence and clinical correlates of abnormal lipid metabolism in young Chinese patients with first-episode drug-naïve major depressive disorder

Abnormal lipid metabolism (ALM) is frequently observed in major depressive disorder (MDD), yet its clinical correlates in young adults remain insufficiently elucidated. The aim of this study was to investigate the prevalence and clinical characteristics of ALM in young adult patients with first-episode drug-naive (FEDN) MDD in the Chinese population. This cross-sectional study involved 1251 young MDD patients (18–44 years old). Data on sociodemographics, clinical symptoms and metabolic parameters were collected. Clinical symptoms were assessed using Hamilton Depression Scale (HAMD), Hamilton Anxiety Scale (HAMA), Positive and Negative Symptom Scale (PANSS-P) and Clinical General Impression Scale (CGI-S). Binary logistic regression and exploratory receiver operating characteristic (ROC) analyses were used to examine clinical and biochemical factors associated with ALM. The prevalence of ALM was 80.3% in young FEDN MDD patients. Compared with patients without ALM, those with ALM had significantly higher HAMD scores (31.00 [29.00, 32.00] vs. 28.00 [26.00, 30.00], Bonferroni-corrected P < 0.001), CGI-S scores (6.00 [5.00, 7.00] vs. 5.00 [5.00, 6.00], Bonferroni-corrected P < 0.001), and TSH levels (5.26 [3.48, 6.84] vs. 3.62 [2.05, 4.47] mIU/L, Bonferroni-corrected P < 0.001). Multivariable logistic regression showed that HAMD score (OR = 1.255, P < 0.001), CGI-S score (OR = 1.563, P = 0.001), and TSH level (OR = 1.223, P < 0.001) were independently associated with ALM. In exploratory, sample-specific and unvalidated ROC analyses, the areas under the curve were 0.74 for HAMD, 0.67 for CGI-S, and 0.72 for TSH; the combination of HAMD and TSH yielded an AUC of 0.78. ALM was common in this clinical sample of young FEDN MDD patients and was cross-sectionally associated with greater depressive severity, higher overall illness severity, and elevated TSH levels. Lipid and thyroid profiles may merit attention in young FEDN MDD patients, but the ROC-derived values should not be interpreted as clinically actionable thresholds. Longitudinal studies are needed to clarify temporal relationships and clinical implications.