Obsessive-compulsive disorder David Veale consultant psychiatrist 1 reader in cognitive behaviour therapy 2 , Alison Roberts clinical psychologist 1 1 Centre for Anxiety Disorders and Trauma, South London and Maudsley NHS Foundation Trust, London SE5 8AZ, UK; 2 Anxiety Disorders Residential Unit, South London and Maudsley NHS Foundation Trust and Institute of Psychiatry, King’s College London Obsessive-compulsive disorder (OCD) is characterised by the presence of obsessions or compulsions, or commonly of both. OCD is the fourth most common mental disorder after depression, alcohol/substance misuse, and social phobia, with a lifetime prevalence in community surveys of 1.6%. 1 The severity of OCD differs markedly from one person to another. People are often able to hide their OCD, even from their own family, although it can cause problems in relationships and interfere with the ability to study or work. Health consequences can also occur: fear of contamination can, for example, prevent the accessing of appropriate health services or lead to dermatitis from excessive washing. When the disorder starts in childhood or adolescence, young people may avoid socialising with peers or become unable to live independently. The World Health Organization ranks OCD as one of the 10 most handicapping conditions by lost income and decreased quality of life. 2 This clinical review summarises the evidence on how to recognise, assess, and manage people with OCD. Who gets OCD? OCD occurs all over the world, although cultural factors may shape the content. (For example, religious obsessions are more common in some communities.) The sex ratio in epidemiological surveys across the world is equal, 1 but more women have compulsive washing, and more men have sexual obsessions, magical numbers, or obsessional slowness. The mean age of onset is late adolescence for men and the early 20s for women. However, OCD can also present in older people, either after a long history of the condition hitherto undiagnosed or with symptoms that are more recent in onset. OCD occurs with a point prevalence of about 1% of the population. 34 Children and adolescents can also have OCD, with a prevalence of about 0.25% in 5-15 year olds. 5 They have a similar presentation to adults. 6 The differences reflect developmental stages (for example, more sexual and religious obsessions in adolescents than in children and more fears of death of a parent for young people than for adults). 6 Rarely, children may develop a sudden onset of obsessive-compulsive symptoms with an episodic course and the presence of motor tics, hyperactivity, or choreiform movements. This is associated with various infectious agents and other environmental factors in several case series of children with OCD. 7 What are obsessions and compulsions? An obsession is defined as an unwanted intrusive thought, doubt, image, or urge that repeatedly enters the mind. Obsessions are distressing and ego-dystonic (that is, they are repugnant or inconsistent with the person’s values). The person usually regards the intrusions as unreasonable or excessive and tries to resist them. A minority of obsessions are regarded as overvalued ideas and, rarely, delusions. 8 Obsessions do not concern day to day worries, which occur in generalised anxiety disorder; perceived defects in appearance, which occur in body dysmorphic disorder; or fear of having a serious disease, which occurs in health anxiety. Compulsions are repetitive behaviours or mental acts that a person feels driven to perform in response to an obsession. They are largely involuntary and are seldom resisted. A compulsion can take the form of either an overt action observable by others (such as checking that a door is locked) or a covert mental act that cannot be observed (such as repeating a certain phrase in the mind). Covert or mental compulsions are generally more difficult to resist or monitor than overt ones, as they are “portable” and easier to perform. The table⇓ lists common obsessions and compulsions. A compulsion in OCD is not in itself pleasurable, which differentiates it from impulsive acts such as shopping, gambling, or paraphilias that are associated with immediate gratification. The term “ritual” is synonymous with compulsion but usually refers to motor acts. “Rumination” in OCD refers to mental acts repeated endlessly in response to intrusive ideas and doubts. The term “pure O” is sometimes used by patients to describe ruminations without observable compulsions. To warrant a diagnosis of OCD, obsessions and compulsions must be time consuming (for example, more than one hour a day) or cause significant distress or functional impairment (see box). 9 10 Hoarding is a compulsion in OCD, but “hoarding disorder” is now planned to be a separate diagnosis in ICD-11 (international classification of diseases, 11th revision). It refers to the Correspondence to: D Veale david.veale@kcl.ac.uk For personal use only: See rights and reprints http://www.bmj.com/permissions Subscribe: http://www.bmj.com/subscribe BMJ 2014;348:g2183 doi: 10.1136/bmj.g2183 (Published 7 April 2014) Page 1 of 6 Clinical Review CLINICAL REVIEW