The changing prevalence and severity of obsessive-compulsive disorder criteria from DSM-III to DSM-IV

Objective: Relative to other mental disorders, the prevalence of obsessive-compulsive disorder (OCD) in the general population is not well established. Some epidemiological surveys have determined the prevalence of DSM-III OCD, but this is one of the first reports, to the authors' knowledge, of DSM-IV OCD's prevalence. Method: Data from the Australian National Survey of Mental Health and Well-Being, a nationally representative epidemiological survey of mental disorders, were analyzed. The prevalence and associated characteristics of DSM-IV OCD were identified, and then the data were rescored for DSM-III OCD. Cases defined by each system were compared. Results: The 12-month prevalence of DSM-IV OCD was 0.6%, considerably less than found in surveys employing DSM-III diagnostic criteria. DSM-IV OCD showed significantly higher levels of comorbidity, disability, health service use, and treatment received. Conclusions: Changes in the reported prevalence and severity of OCD between DSM- III and DSM-IV cases are most likely a function of the differences in diagnostic criteria between DSM- III and DSM-IV.