Plasma Sphingomyelin and Ceramide Profiles as Potential Biomarkers in Young Adults with Bipolar Depression: A Lipidomics Study

Background

Bipolar depression (BPD) lacks reliable peripheral biomarkers for early diagnosis. Sphingomyelin (SM) and ceramide (Cer) are bioactive lipids implicated in neuronal membrane signaling, yet their diagnostic utility in young adults with BPD remains unclear. Patients and Methods: We conducted a single-center exploratory untargeted lipidomics study focusing on SM and Cer species in plasma from 26 young adults (18– 26 years) with BPD at baseline and after three weeks of quetiapine and magnesium valproate treatment (BPD3w), alongside 27 sex- and age-matched healthy controls (HC). Group comparisons of total SM, total Cer, and SM/Cer ratio were performed; ROC curves assessed discriminative ability. A Venn diagram approach, followed by LASSO regression with bootstrap averaging, identified a refined candidate biomarker panel from 140 SM/Cer species.