Schizophrenia and Co-Occurring Substance Use Disorder

Abstract

A 29-year-old Caucasian man was brought to the emergency department by the police after he was found wandering barefoot through the snow on Main Street. The police had been called after passers-by reported that the man seemed intoxicated and was acting strangely. When an officer approached the man, he became belligerent and agitated and angrily exclaimed that they had no reason to question him. Using some force, the police brought him to the emergency department. The psychiatrist who interviewed him noted a strong smell of alcohol and signs of psychosis; the man demonstrated a clear thought disorder, and he appeared to be responding to internal voices. A physical examination was unremarkable. His urine was positive for cannabis by dipstick test, and an alcohol breath test was positive. Given the absence of further information about him, the patient was admitted to the crisis service, where he promptly fell asleep. Four hours later, he was less intoxicated. A history was obtained and a mental status examination was performed. As far as could be determined, he had been receiving treatment at a local mental health center, but he had stopped taking his medication (risperidone) 4 weeks earlier and had relapsed to heavy use of alcohol and cannabis. During this period he had been essentially homeless, a situation that presented increasing difficulty for him given the recent cold weather and snow. How commonly does schizophrenia cooccur with substance use disorder? What are the implications of substance use for the course of the psychosis? What do we understand about the basis of the co-occurrence of substance use disorder and schizophrenia? How best can a psychiatrist work with this type of a patient? What medications are most likely to be helpful?