Open access. Letter. Obsessive–compulsive and related disorders are defined in DSM-5 and include obsessive–compulsive personality disorder1 (OCPD) or anankastic personality disorder in ICD-10.2 Its prevalence is believed to be 1–2% in the general population, but it occurs much more frequently in psychiatric populations3 and is under-recognised and poorly researched,4 although it is beginning to gather greater awareness.5