Substance use disorder and schizophrenia: prevalence and sociodemographic characteristics in the Latin American population

Interest in understanding the comorbidity of schizophrenia and substance use disorder has been increasing due to the increase of this diagnosis, to the negative effects observed in the subject and to the health service costs. This dual disorder can have dramatic effects on the clinical course of the psychiatric disorder, this being, for example increased relapses, re-hospitalizations, more severe symptoms, noncompliance with antipsychotic medication, marked mood changes, increased rates of hostility and suicidal ideation as well as in other areas of functioning, including interpersonal violence and victimization, homelessness, and legal problems. Literature from the United States and Europe in particular suggests that the prevalence rates for this dual diagnosis may range from 10 to 70%. In this study, we have reviewed the prevalence of the dual diagnosis of schizophrenia and substance use disorder as well as the sociodemographic characteristics in the literature on Latin-American populations. Notwithstanding that the dual disorder is a widely accepted diagnosis, relatively little is known about its prevalence in Latin American populations or about the environmental factors that may influence it, as well as about the demographic, clinical, and other characteristics of these individuals. A better understanding of this diagnosis might improve the methods for the detection and assessment of substance use disorder in persons with severe mental illness such as schizophrenia.