Notably, these AUC values fall within the range reported for other biomarker-based models in cocaine- and stimulant-related conditions, such as plasma inflammatory mediators distinguishing primary from cocaine-induced major depression (AUC 0.867–0.914), serum HSP70 for cocaine dependence (AUC 0.948) and peripheral exosomal miR-184-3p for methamphetamine use disorder (AUC 0.823–0.902), although the differences in clinical phenotype, tissue source and study design preclude direct quantitative comparison [36,37,38]. The gene discussed is HSPA1A; the disease is major depressive disorder.