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obsessive compulsive disorder (OCD)

This factsheet is also available as a pdf.


People with OCD have frequent intrusive, distressing thoughts often accompanied by compulsive, ritualised behaviours. Those with the condition typically feel compelled to perform repetitive behaviours to relieve distress linked to their persistent ruminations and doubts, and often have false beliefs that such actions will prevent something bad from happening such as harm to themselves or others.


Obsessive ruminations commonly include fear of contamination by germs, other fears regarding safety, or a need for order and symmetry. Compulsive behaviours can include repetitive actions like checking appliances, excessive cleaning, and hoarding, or repetitive mental acts, such as counting, repeating words silently or praying. People with OCD may have additional problems including depression and substance misuse, and the condition often occurs alongside anxiety disorders, all of which are characterised by exaggerated fears and behaviours to avoid confronting those fears.

How is it recognised?

OCD is usually brought to the attention of healthcare professionals when symptoms become so acute they interfere with daily functioning.  OCD can’t yet be diagnosed with medical tests despite being considered to, at least partially, have biological roots. Structured clinical interviews and rating scales are used to determine the severity of symptoms. It is common for the condition to be hidden for many years and families can play an important role in encouraging people to seek help.


Who does it affect?

OCD affects around 1-2% of the UK population, regardless of gender or background.  Several factors contribute to development such as genetics, brain differences and upbringing.  Stressful life events can trigger OCD and there have been rare cases following severe infection with streptococcal bacteria. On average OCD manifests during late teens for men and early twenties for women.



NICE recommend people with OCD should undergo Cognitive Behavioural Therapy (CBT). Those who are severely affected are usually offered an intense course of CBT and recommended antidepressant medication to reduce symptoms.


Further reading

NICE guidance on treatment of OCD

NHS Choices information page

This is a fact sheet issued by the Science Media Centre to provide background information on science topics relevant to breaking news stories. This is not intended as the ‘last word’ on a subject, but rather a summary of the basics and a pointer towards sources of more detailed information. These can be read as supplements to our roundups and/or briefings.

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