Schizophrenia and smoking addiction

Introduction and Objective: The aim of this study is to examine the relationship between schizophrenia and cigarette addiction. Method: This cross-sectional study was conducted at the Psychiatry Outpatient Clinic of Akdeniz University Hospital. The study included 80 patients diagnosed with schizophrenia according to DSM-5 diagnostic criteria, who had no additional psychiatric or neurological diagnoses, no alcohol or substance use disorder, were literate, aged between 18-65, and voluntarily participated in the study. Among them, 40 patients were smokers, while 40 were non-smokers. Data collection tools included the Positive and Negative Syndrome Scale (PANSS), the Montreal Cognitive Assessment Test (MoCA), the Fagerström Test for Nicotine Dependence (FTND), and a Sociodemographic and Clinical Data Form prepared by the researchers. Results: The median age of the participants was 36 (30-44) years, and 50% (n=40) were female. Among the smoking patients, the average smoking quantity was 22.88±17.15 pack-years. According to the FTND, 35% of smokers were categorized as having very high dependence, while 27.5% had high dependence. The PANSS positive symptom score, PANSS negative symptom score, PANSS general psychopathology score, PANSS total score, and all individual item scores except for "orientation disorder" were significantly higher in smoking patients compared to non-smokers. MoCA scores were significantly higher in non-smoking patients than in smokers. In the multivariate logistic regression analysis, PANSS total score (OR: 1.275, 95% CI: 1.121-1.450; p<0.001) was identified as an independent risk factor for smoking. In the linear regression analysis predicting MoCA scores, PANSS positive symptom score (t=-7.062; p<0.001; 0.625-fold), PANSS negative symptom score (t=-8.103; p<0.001; 0.676-fold), PANSS general psychopathology score (t=-8.144; p<0.001; 0.678-fold), and PANSS total score (t=-8.736; p<0.001; 0.703-fold) were significantly associated. Conclusion: It can be concluded that schizophrenia patients who smoke have more severe illness, lower cognitive functioning, and that PANSS total score is an independent risk factor for smoking behavior. Additionally, disease severity and cognitive functions are related. More studies are needed to better understand and define the relationship between schizophrenia and cigarette addiction and to develop appropriate interventions. Keywords: Schizophrenia, Smoking, Addiction, Cognitive Functions, Psychopathology