Medical Comorbidity in Patients with Schizophrenia and Alcohol Dependence

Background: Schizophrenia and alcohol dependence are major risk factors for a variety of medical problems, yet there has been little research on the medical status of patients in whom both conditions coexist.

Methods: We assessed the prevalence and severity of medical illness in 80 patients with schizophrenia or schizoaffective disorder and comorbid alcohol use disorders who entered a controlled trial of monitored naltrexone treatment, and analyzed the relationship between medical illness burden and demographic variables, alcohol and other substance use, and psychosis. Participants underwent physical examination, laboratory tests, medical record review and standardized assessments of medical illness burden, alcohol and other substance use, and psychosis. Nested block multiple regression analyses were used to assess the contribution to illness burden made by demographic variables, alcohol and substance use, and psychosis severity.

Results: 83% of participants had at least one chronic medical illness, hypertension being the most common (43%). Medical comorbidity in this cohort was more severe than for schizophrenia patients in the CATIE trial (Chwastiak, L., Rosenheck, R., McEvoy, J.P., Keefe, R.S., Swartz, M.S., Lieberman, J.A., 2006. Interrelationships of Psychiatric Symptom Severity, Medical Comorbidity, and Functioning in Schizophrenia. Psychiatr. Serv., 57(8), 1102-1109.); the prevalence of hypertension, chronic obstructive pulmonary disease, and coronary artery disease, was more than twice greater. Medical illness burden correlated with alcohol use severity, but appeared to be independent of other substance use or psychosis severity.

Conclusions: Patients with co-occurring alcohol use disorder may have significantly more medical illness burden than patients with schizophrenia or schizoaffective disorder alone. Interventions to reduce alcohol use may be necessary to lessen medical morbidity.