Epidemiology and comorbidity of obsessive-compulsive disorder in late adolescence: a cross-sectional study in senior high schools in Greece.

Objective: The aim of this study was to examine the epidemiology, comorbidity and use of health services of obsessive-compulsive disorder (OCD) and subclinical obsessive-compulsive symptoms in late adolescence.

Methods: A total of 2427 adolescents attending senior high schools in Greece were selected for a detailed psychiatric interview using the revised clinical interview schedule (CIS-R). Use of alcohol, nicotine and cannabis, and several socio-demographic and socio-economic variables were also assessed.

Results: The prevalence of OCD was 1.39% (95% confidence interval [CI]: 1.05-1.84) while that of subclinical obsessive-compulsive symptoms was 2.77% (2.22-3.45). There was a female preponderance for subclinical symptoms. Financial difficulties of the family was the only socio-demographic variable that was significantly associated with OCD but not with subclinical symptoms. The pattern of comorbidity was similar for both conditions but milder in the subclinical form. About one in three reported use of general health services and one in ten use of psychiatric services.

Conclusions: OCD and subclinical obsessive-compulsive symptoms were relatively common. Comorbidity with other psychiatric disorders and use of substances was considerable even in subclinical status, but use of specialised health services was small. Clinical and research implications are discussed.