Illness-related outcomes of illicit substance use disorder in adolescents with early onset schizophrenia: a multicenter study

ObjectivesLifetime co-occurring substance use disorders are common at the time of presentation for the treatment of primary psychosis. Our aim was to investigate the clinical characteristics of adolescents with early-onset schizophrenia/schizoaffective disorder (EOS), categorized as either with (EOS + SUD) or without SUD (non-SUD/EOS), in a multi-center sample.MethodsBetween 2016 and 2022, 255 patients were evaluated across three tertiary-care inpatient units. Diagnoses were confirmed by the treating physician according to the DSM-5 during the hospital stay. The severity of symptoms was measured using the Positive and Negative Syndrome Scale (PANSS).ResultsThe EOS + SUD group exhibited a higher illness onset, fewer years of education, longer duration of untreated psychosis (DUP), a higher frequency of male gender, more frequent hospitalizations, increased use of clozapine and zuclopenthixol LAI, along with higher rates of post-traumatic stress disorder and conduct disorder. Notably, differences in DUP, clozapine use, and the number of hospitalizations did not persist in the multivariate logistic regression model.ConclusionsOur findings support the notion of SUD playing a role in modifying the course of illness in EOS. Future studies should emphasize exploring treatment responses to medications and interventions among youth with dual diagnoses.