Gale-Grant O, et al. - In view of the observed high frequency of comorbid mental illness in individuals receiving opioid substitution therapy, researchers examined a cohort of individuals receiving therapeutic methadone or buprenorphine to determine the rates of co-prescribing and psychiatric comorbidity among these patients. From the comprehensive electronic medical records at a single center in London, United Kingdom, they included 610 individuals in the final analysis. Outcomes revealed high rates of psychotropic co-prescribing, with 36.7% of individuals undergoing a psychotropic medication in addition to their opioid substitution drug, including 35.4% receiving an antidepressant, 9.2% an antipsychotic, 8.6% a benzodiazepine, and 4.5% a gabapentinoid. These rates are far in excess of the local population prescription frequency; for an unlicensed indication, 75.5% of antipsychotic prescriptions and 47.7% of benzodiazepine prescriptions were made. For individuals receiving opioid substitution therapy, they suggest the necessity for evidence-based treatment of comorbid mental illness.