OCD (Obsessive Compulsive Disorder) is a condition characterised by distressing obsessive or ruminating thoughts, which in turn lead the person to perform certain actions compulsively. Common obsessions include contamination, thoughts about order or organisation and religious or sexual thoughts. Common compulsions include checking, cleaning, counting or ordering.

The presence of insight usually distinguishes OCD from psychotic illnesses, with individuals usually recognising the obsessive thoughts as their own.

It is usually a chronic disorder and is ranked by the World Health Organisation in the top ten of the most disabling illnesses by lost income and decreased quality of life.

What we already know

OCD is commonly viewed as an anxiety disorder and is strongly associated with other anxiety disorders. It also has a high level of comorbidity with depression.

Effective treatments include Cognitive Behavioural Therapy (including Exposure and Response Prevention), self-help groups, antidepressants and combined psychological and pharmacological treatments.

Areas of uncertainty

The aetiology of OCD remains unclear. Biological and psychological causal theories have been proposed, as well as genetic changes that may predispose certain individuals to the disorder.

A challenging area is the detection and treatment of OCD in children and we still know little about the links between OCD and mortality and suicide.

If the initial response to treatment with antidepressants is poor, there are augmentation strategies, including antipsychotics and other pharmacological treatments, although little is known about the definitive approach when using these.

What’s in the pipeline?

Existing medications for OCD mainly target the neurotransmitters serotonin and dopamine. However, there has been a proposed theory that symptoms result from an imbalance of the neurotransmitter glutamate, providing a new focus for future research.

Research is also ongoing into the role of electroconvulsive therapy, neurosurgery and deep brain stimulation in treating OCD.


‘Obsessive compulsive disorder’ NICE evidence update 47, Sep 2013 [PDF]

‘Obsessive-compulsive disorder: core interventions in the treatment of obsessive-compulsive disorder and body dysmorphic disorder’ NICE clinical guideline 31, 2005 [PDF]

‘Obsessive-compulsive disorder and body dysmorphic disorder’ NICE Pathway [PDF]

Common mental health disorders: Identification and pathways to care. NICE, CG123, May 2011. [PDF]

Semple, D. and Smyth, R. (eds.) (2013) Oxford Handbook of Psychiatry. 3rd ed. Oxford: Oxford University Press [Publisher]


Written by: Josephine NealePatrick Kennedy-Williams
Reviewed by:
Last updated: Sep 2015
Review due: Sep 2016

Our OCD Blogs

Guided self help and cCBT for OCD: OCTET finds low adherence and uncertain fidelity


Alan Underwood reports on the new OCTET trial published last week, which fails to find any support for the use of low-intensity guided self-help or computerised CBT for people with obsessive compulsive disorder (OCD).

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#MQScienceMeeting: transforming lives with better mental health research


André Tomlin looks back at the #MQScienceMeeting Mental Health Science Meeting that took place in London on 2-3 Feb 2017.

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OCD risk may increase following perinatal complications


Alan Underwood summarises a population based cohort study of 2.4 million Swedish children, which highlights links between perinatal risk factors such as smoking during pregnancy, and later development of obsessive compulsive disorder.

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Antidepressants and psychotherapy for OCD in adults: network meta-analysis


Alan Underwood summarises a recent network meta-analysis of medication and talking treatments for OCD (obsessive-compulsive disorder) in adults.

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Psychiatric disorders: what’s the significance of non-random mating?


Marcus Munafo considers the implications of a recent Swedish population study, which explores patterns of non-random mating within and across 11 major psychiatric disorders.

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Experience sampling and ecological momentary assessment for studying anxiety disorders


Alan Underwood publishes his debut Mental Elf blog on a narrative review of experience sampling and ecological momentary assessment for studying the lives of people with anxiety disorders.

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Short-term psychodynamic psychotherapy for all common mental health disorders?


For his ninth Mental Elf blog, Mark Smith reports on a Cochrane systematic review of the effectiveness of short term psychodynamic therapies on common mental health disorders.

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Family-based CBT for early childhood OCD: efficient for white, non-minority, upper middle-class children


Ioana Cristea reviews a recent RCT of family-based CBT for early childhood OCD and concludes that the results are impressive, but may not be applicable to poorer children from ethnic minorities.

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Meta-review presents the risks of all-cause and suicide mortality in mental disorders


This recent and well-conducted meta-review concludes that the impact on mortality and suicide of mental disorders is substantial, and probably poorly appreciated as a public health problem. Raphael Underwood’s blog summarises the data for all-cause and suicide mortality in mental disorders.

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Latest evidence from NICE on Obsessive Compulsive Disorder (OCD) and Body Dysmorphic Disorder (BDD)

Many of the drug treatments included in this report are not currently approved for use in the UK

Obsessive compulsive disorder (OCD) is a condition that has recently been given a significant amount of TV airplay and media coverage, perhaps most notably in the Channel 4 documentary Jon Richardson: A little bit OCD, which received mostly good reviews from mental health groups. Despite this reasonable public profile, our knowledge about the best way [read the full story…]