Obsessive Compulsive Disorder (OCD)

Definition and characteristics of OCD

Obsessive-compulsive disorder is a psychiatric condition in which the individual experiences intrusive, repetitive obsessions or compulsions that are anxiety provoking or time-consuming or cause a significant impairment in normal everyday functioning.

This definition is taken from the Diagnostic and Statistical Manual, 4th ed. (DSM-IV, 1994) of the American Psychiatric Society.

The DSM-IV also provides a set of defining characteristics for obsessions and compulsions as listed below.

Obsessions are defined by the following:

  • Repetitive persistent thoughts, impulses, or images that are experienced as intrusive and inappropriate and that cause marked distress
  • The obsessions are not simply excessive worries about real life problems
  • The person attempts to negate or inhibit such thoughts impulses or images or to neutralize them with some other thought or action
  • The person recognizes that the obsessional thoughts, impulses, or images are a product of his or her own mind.

Typical obsessions are recurring thoughts about contamination e.g. getting hands dirty or recurring doubts that one has forgotten to carry out some necessary actions e.g. locking the door or turning off the stove.

Compulsions must meet the following criteria:

  • Repetitive behaviors or mental acts that the person feels forced to carry out in response to an obsession, or according to rules that must be applied rigidly.
  • Behaviors or mental acts are aimed at preventing or reducing distress or preventing some dreaded event or situation. However these behaviors or mental acts either are not connected in a realistic way with what they are designed to neutralize or prevent or clearly are excessive.

It is to be noted that the compulsive actions are not carried out for pleasure or gratification. But rather, the person feels compelled or forced to carry out the acts because they believe that doing so will reduce the distress that accompanies an obsession or to prevent some feared event from happening.

For example, someone with an obsession that they must stay absolutely clean in order to prevent disease may try to reduce their distress by repeatedly washing their hands sometimes to the point of making their skin raw.

Lifetime prevalence of OCD

A large epidemiological US survey found a lifetime prevalence for obsessive compulsive disorder of 1.6% making it one of the least prevalent of the anxiety disorders (Kessler et al, 2005). However because of its debilitating nature, obsessive-compulsive disorder, although rare, still puts a relatively high burden on the mental health system.

Causes (Aetiology)

There are a number of hypotheses and psychological theories regarding the causative mechanism for OCD. One of the earliest, proposed by Sigmund Freud, and still advocated by some (Shapiro and Stewart, 2011) is that pathological guilt may play a role. Franklin and Foa (2011) in a recent paper have reviewed in detail behavioural and cognitive theories and these are the bases for the main treatment approaches as described in the next section.

Treatments for Obsessive Complusive Disorder

It is important that persons with OCD receive treatment because those with the condition experience so much psychological and emotion suffering and diminished quality of life.

Specifically, Torres et al (2006) in a UK sample of over 8580 persons found that 55% of those with OCD had only obsessions and no compulsions.

They also found that 37% of those with OCD also had a major depressive disorder, 31% generalized anxiety disorder, 25% had attempted suicide, 22% agoraphobia or panic disorder and 20% alcohol dependence.

Fortunately, a lot of progress has been made in the past 40 years both in the development and evaluation of treatments for obsessive-compulsive disorder. Treatment approaches include:

  • Cognitive Behavioral Therapy (CBT) incorporating “exposure plus response prevention EX/RP). Current protocols for this approach are based on a blended cognitive and behavioural theoretical model (Foa & Kozak, 1986) and include gradual exposure to obsessional stimuli, gradual blocking of the usual compulsive ritualistic response, and discussion of erroneous beliefs.
  • Pharmacotherapy. These include selective serotonin reuptake inhibitors (SSTRI) but generally only partially effective.
  • Self-help . A new format has been recently introduced namely online help (Moritiz 2011).


American Psychiatric Association. (2000). Diagnostic and statistical manual of mental disorders. (4th ed., text rev.) Washington, DC: Author.

Franklin, M. E., & Foa, E. B. (2011). Treatment of obsessive compulsive disorder. Annual Review of Clinical Psychology, 7, 229-243.

Foa, E.B. & Kozak, M.J. (1986). Emotional processing of fear: exposure to corrective information. Psychological Bulletin, 99, 20-35.

Kessler, Ronald C., Berglund, Patricia, Demler, Olga, Jin, Robert, Merikangas, K. R., Walters, Ellen E., (2005). Lifetime Prevalence and Age-of-Onset Distributions of DSM-IV Disorders in the National Comorbidity Survey Replication. Archives of General Psychiatry, Vol. 62(6), 593-602.

Moritz, S., Wittekind, C. E., Hauschildt, M., & Timpano, K. R. (2011). Do it yourself? Self-help and online therapy for people with obsessive-compulsive disorder. Current Opinion in Psychiatry, 24(6), 541-543.

Oxford Dictionary of English (2nd ed. revised). (2005). Oxford, UK: Oxford University Press.

Shapiro, L. J., & Stewart, S. E. (2011). Pathological guilt: A persistent yet overlooked treatment factor in obsessive-compulsive disorder. Annals of Clinical Psychiatry, 23(1), 63-70.

Torres AR, Prince MJ, Bebbington PE, Bhugra D, Brugha TS, et al. 2006. Obsessive-compulsive disorder: prevalence, comorbidity, impact, and help-seeking in the British National Psychiatric Morbidity Survey of 2000. Am. J. Psychiatry 163:1978–85.