Objectives About half of young adults with early psychosis also have substance use disorders (SUD). For young adults with first episode psychosis (FEP), the persistence of SUD negatively impacts the symptomatic and functional outcome as well as the management of the problems. This article aims to identify and synthetize the best therapeutic approaches for the treatment of young adults with concurrent disorders (FEP and SUD) and to present avenues for practical and adapted approaches for the assessment and follow-up of people with concurrent FEP and SUD. Method Narrative literature review on the treatment of young adults with concurrent disorder (FEP and SUD). Results Several studies demonstrate the usefulness of early intervention for psychosis services (EIS) in the management of SUD with approximately 50% decrease in SUD during the first year of follow-up. A variety of therapeutic interventions have been studied, but none have demonstrated substantial long-term superiority over the standard treatment offered in EIS. The studies also have several methodological limitations. To date, clinical guidelines suggest offering an adapted and integrated treatment for psychosis and SUD and recommend the use of various approaches such as case management, comprehensive assessment and feedback on SUD and psychosis as well as their interplay, harm reduction interventions, motivational interviewing, cognitive behavioural therapy, and pharmacotherapy. It is proposed here to proactively adjust the treatment to consider the severity of the disorders, their impact on the various dimensions of psychosis outcomes, the developmental stage of the young person and his or her stage of change with respect to substance use. Conclusion Data on best practice in the treatment of concurrent PEP-SUD disorders are relatively limited. Some approaches appear to have the potential to improve the clinical course of young people living with such conditions, especially if they are adapted to this population. Furthermore, research and innovations in the management of concurrent disorders must continue to offer better adapted care to young adults with early psychosis and SUD.