The Oxytocin-Schizophrenia-Addiction Triangle: A Hypothesis for Understanding High Smoking Prevalence in Psychotic Disorders Through Dysregulated Social Reward Circuitry

Individuals with schizophrenia exhibit extraordinarily high rates of smoking (60-90%) and substance use disorders (42% lifetime prevalence), yet the neurobiological mechanisms underlying this comorbidity remain incompletely understood. This paper proposes that oxytocin system dysregulation serves as a unifying mechanism connecting psychotic disorders with addiction vulnerability. Drawing on converging evidence from human studies and animal models, the hypothesis integrates with the broader Oxytocin-Dopamine Convergence Model and generates specific, testable predictions for understanding and preventing substance use in this high-risk population.