Obsessive-compulsive disorder - A state-of-the-art review.

Obsessive-compulsive disorder (OCD) is a severe and common mental illness associated with high rates of treatment resistance. Quality of life is significantly impaired by OCD, and there is a high risk of chronification without treatment. The rationale of this narrative review is to present the state of the art about OCD regarding its A) relevance, course, and impact on wellbeing, B) risk factors, C) etiopathophysiology, D) clinical manifestation and classification criteria, E) comorbidity and differential diagnostics, F) diagnostic investigations, G) secondary obsessive-compulsive syndromes, and H) treatment approaches. Finally, the consequences of novel developments for the diagnosis and treatment of individual patients are summarized, and the needs for further research are outlined.