Association of serum lipid levels with psychotic symptoms in first-episode and drug naïve outpatients with major depressive disorder: a large-scale cross-sectional study

Background Major depressive disorder (MDD) is a prevalent psychiatric disorder, with increasing evidence that patients with MDD display psychotic symptoms. Studies have shown the association between lipid levels and MDD, but few have explored the relationship between lipids and psychotic symptoms in MDD. The objective of this study was to compare the differences of lipid levels between patients with psychotic major depressive disorder (PMD) and those with non-psychotic major depressive disorder (NPMD) in first-episode and drug-naive (FEDN) MDD patients. Methods A total of 1718 outpatients with FEDN MDD were recruited. In addition to collecting basic information, their blood specimens were also collected to detect serum TC, HDL-C, TG, and LDL-C. The Hamilton depression scale (HAMD), Hamilton anxiety scale (HAMA), and Positive and Negative Syndrome Scale (PANSS) were used to assess their depression, anxiety, and psychotic symptoms respectively. Results Compared to those with NPMD, those with PMD had higher scores on HAMD, HAMA, and more elevated serum TC, TG, and LDL-C levels, but lower HDL-C levels (all p < 0.05). Further logistic regression analysis showed that TG, the severity of depressive and anxiety symptoms were significantly associated with psychotic symptoms (p < 0.05). Limitations No causal relationship could be drawn due to the cross-sectional design. Conclusions Psychotic symptoms in patients with MDD may be predicted by lipid levels in the future. Our findings suggest that TG seems to predict the presence of current psychotic features among patients with FEDN MDD.