Prevalence of psychosis and its relationship with substance use disorder in patients with bipolar disorder in Iran

Background The correlation between psychosis and bipolar disorder is a crucial and complex matter that requires attention and study. In this study, researchers examined the relationship between the current episode status, substance use disorder, different types of substance use, and psychotic symptoms in inpatients with bipolar disorder. Methods The study included 150 patients who were diagnosed with bipolar disorder based on the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5). These patients were referred to the emergency department of Roozbeh Psychiatric Hospital in Iran between November 2019 and February 2020. The Structured Clinical Interview for the DSM-5 (SCID-5) questionnaire was used to diagnose the patient's bipolar disorder, including episodes of depression and mania, as well as their substance use disorder. The type of substance used and the pattern of its use were also evaluated using this questionnaire. Additionally, a faculty member of the psychiatry department at Tehran University of Medical Sciences carefully evaluated the patient's condition for the presence of psychotic symptoms using a psychiatric diagnostic interview. Results Out of 150 inpatients diagnosed with bipolar disorder, 89 (59.3%) had comorbid substance use disorder. Among these 89 patients, 42 (47.2%) had psychotic symptoms, whereas 79 (52.7%) of the total 150 inpatients had psychotic symptoms. There was no significant relationship between substance use disorder (p-value=0.86), the type of substance used in a recent episode (p-value=0.93), and the current episode type (p-value=0.69) with psychotic symptoms. Limitations The study's generalizability is limited to hospital patients with bipolar disorder. Additionally, since it was a cross-sectional study, causal interpretation was not possible. Conclusions The study suggests a primary link between bipolar disorder and psychosis, independent of substance use. Longitudinal multicenter studies with larger sample sizes are recommended.