Phenomenology

Abstract Obsessive–compulsive disorder (OCD) and obsessive–compulsive related disorders (OCRDs) are common lifespan illnesses that cause substantial suffering. Patients may hide symptoms, and OCD and OCRDs are frequently overlooked by health professionals. Factor analyses consistently identify particular symptom clusters in OCD. Direct enquiry about OCD and OCRDs can help accurately identify these conditions. Measures for screening, diagnosis, and assessing OCD and OCRDs symptom severity are available.