Emine Merve AKDAĞ, Çetin TURAN
The European Research Journal - 2026;12(9):997-1010
Objective: To evaluate the inflammatory profiles in individuals with methamphetamine use disorder (MUD), methamphetamine-associated psychosis (MAP), schizophrenia, and healthy controls by comparing C-reactive protein (CRP) and hemogram-derived inflammatory markers. Methods: This retrospective study included 280 male participants divided into four age-, body mass index -, and smoking status-matched groups (n = 70 each): MUD, MAP, schizophrenia, and healthy controls. All patients had been free from psychotropic treatment for at least 2 months prior to blood sampling. CRP, neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-CRP ratio (LCR), systemic immune-inflammation index (SII), systemic inflammation response index (SIRI), and pan-immune-inflammation value (PIV) were analyzed. Multinomial logistic regression and receiver operating characteristic (ROC) analyses were performed. Results: Compared with healthy controls, all patient groups showed significantly higher CRP, NLR, MLR, SII, SIRI, and PIV levels alongside lower LCR values. Patients with MAP exhibited significantly higher SIRI and PIV levels than those with schizophrenia. Multinomial logistic regression identified NLR, PIV, and SIRI as the biomarkers most strongly associated with MAP. ROC analyses demonstrated that PIV, SIRI, and CRP provided the highest discriminatory performance, particularly in distinguishing MAP and MUD from healthy controls. Conclusions: MUD, MAP, and schizophrenia share common inflammatory alterations; however, MAP is characterized by a greater inflammatory burden, as specifically reflected by elevated SIRI and PIV. These inexpensive and readily accessible hematological indices may serve as adjunctive biomarkers for investigating the biological mechanisms underlying psychosis and methamphetamine-related disorders.
