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

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.

[read the full story...]

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.

[read the full story...]

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.

[read the full story...]

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.

[read the full story...]

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.

[read the full story...]

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.

[read the full story...]

Patients with anxiety disorders are more likely to have suicidal thoughts and actions, says recent review


Suicidal thoughts and actions are typically discussed in relation to depression, but a number of studies have suggested suicide may also be linked to anxiety disorders. Anxiety disorders often co-occur with depression, and this may be masking a risk of suicide specifically related to anxiety. Today is World Suicide Prevention Day so it seemed relevant [read the full story…]

New evidence update from NICE on common mental disorders

nhs evidence eye

The NICE guideline on common mental disorders (PDF) was published back in May 2011, which means that it only included evidence published up until the end of 2010. This is a fast moving field, so NICE have now put out an evidence update, which focuses on new evidence published from Sept 2010 to Oct 2012. This [read the full story…]

NICE clinical case scenarios aim to help GPs improve diagnosis and management of common mental health disorders


NICE has developed a series of case studies for GPs to help apply the recommendations from the Common mental health disorders guideline to practice. The case studies which are informed by clinical experience, include contributions from GPs, clinical psychologists and psychiatrists to help GPs when considering the range of treatments and approaches that are recommended [read the full story…]

Self-help interventions are effective treatments for social phobia and panic disorder, says new meta-analysis


The demand for psychological therapies far outstrips the supply and in this ongoing period of austerity we surely need to produce some cost-effective alternatives. One method that patients can attempt pretty much on their own is self-help provided through books, CDs, DVDs and websites. This new systematic review claims to be the first to bring [read the full story…]