Opioid use and schizophrenia.

PURPOSE OF REVIEW: To summarize the current literature regarding comorbid schizophrenia and opioid use disorder (OUD). RECENT FINDINGS: Epidemiological evidence is unclear on whether patients with schizophrenia have a higher rate of OUD. Patients with OUD have been shown to have a higher risk of developing schizophrenia. However, it is clear that patients with both schizophrenia and OUD are less likely to receive standard of care including medication-assisted treatment (MAT) for opiate use disorder and have worse outcomes compared with patients with schizophrenia who do not abuse opioids. OUD significantly increases the risk of converting patients from prodromal schizophrenia states to schizophrenia or schizoaffective disorder. Shared pathophysiology involving the kappa opioid receptor may help explain the relationships between schizophrenia and OUD. Second-generation antipsychotics, long-acting injectables, and MAT for OUD should be utilized in a dual-diagnosis and treatment approach for patients with schizophrenia and OUD. SUMMARY: Exploration into the relationship between schizophrenia and opiate abuse is still in its infancy and requires a significant amount of future attention to clarify the epidemiology of this comorbidity, neurobiological relationship, shared genetic underpinnings, and possible treatments for both the psychotic symptoms and substance abuse.