The Netherlands OCD association Study (NOCDA) was conducted from 2008-2016 and included 419 OCD patients in a multi-centre prospective study, in order to determine psychological and social determinants of chronicity in a large and representative clinical sample. Data on the treatment received and other use of health care services in between measurements were carefully monitored. Seven mental health care centres have joined forces to perform the baseline measurements (GGZ inGeest, Meerkanten, GGZ Nijmegen, the Overwaal clinic, Adhesie GGZ Midden-Overijssel, LUMC and GGZ Noord- en Midden-Limburg).
OCD (Obsessive Compulsive Disorder) is a debilitating anxiety disorder, which was listed as the 10th most disabling medical disorder in the WHO burden of disease study. Although once considered rare, recent estimates indicate that OCD has a lifetime prevalence rate of approximately 2% worldwide. OCD is characterized by recurrent intrusive and anxiety-provoking thoughts or images and repetitive compulsive behaviours. The disorder tends to interfere with the ability to work and the ability to form healthy relationships with others. In half of the patients, the disorder runs a chronic course despite adequate treatment.