NEFL and major depressive disorder: Looking at individual PPD (details in Supporting Information Figures 1 and 2), there was a greater proportion of patients with high NfL profiles in schizophrenia (37%) and Other PPD (33%), compared to other groups (MDD 19%, FND 12.5%, BPAD 0%), although these exploratory findings should be interpreted with caution given the small sub‐group numbers.