Substance Use, Hospitalizations, and Co-Occurring Disorders among Patients Transferred from a Needle Exchange Program to Opioid Maintenance Treatment.

Opioid use disorders (OUD) is a relapsing condition with high mortality. Opioid maintenance treatment (OMT) reduces heroin use, and overall morbidity and mortality. The prevalence of psychiatric and substance use disorders, potential baseline predictors for psychiatric hospitalization, and psychiatric diagnoses at follow-up were investigated and may give hints about possible preventative strategies. The medical records for 71 patients were reviewed 36 months following referral to OMT from a needle exchange program (NEP). Their psychiatric diagnoses and hospitalizations were identified. Their baseline characteristics were assessed for potential differences between hospitalized versus non-hospitalized patients and between patients with and without psychiatric diagnoses in a longitudinal observational study without controls. A regression analysis was performed to identify predictors for hospitalization when controlling for OMT status. Sixty-five percent of the patients were hospitalized at least once with a psychiatric diagnosis. Substance-related reasons were prevalent, and detoxification occurred among 59% of patients, with sedative- hypnotics (benzodiazepines, zopiclone, zolpidem, and pregabalin) being the substance used by 52% of patients. Baseline use of these drugs and/or buprenorphine predicted for hospitalization when controlling for OMT status. During the follow-up period, 72% of patients met the criteria for a psychiatric diagnosis other than OUD. The prevalence of non-substance use disorders overlapping with SUD was 41%, and that overlapping with anxiety disorder was 27% of all participants. Increased attention to psychiatric co-occurring disorders in the treatment of OUD is required and the importance of addressing sedative-hypnotics use when initiating OMT is highlighted.