Clinical features

The ICD 10 (International Classification of Diseases) definition of Obsessive Compulsive Disorder (OCD) is:

Either obsessions or compulsions (or both) present on most days for a period of at least two weeks.

Obsessions (thoughts, images or ideas) and compulsions share the following features, all of which must be present.

• Acknowledged as originating in the mind of the patient
• Repetitive and unpleasant; at least initially or early in the illness recognised as excessive or unreasonable.
• At least one must be unsuccessfully resisted (although resistance may be minimal in some cases)
• Carrying out the obsessive thought or compulsive act is not intrinsically pleasurable

Obsessions are unwanted ideas, images or impulses that repeatedly enter a person’s mind. Although the person recognises that they are self generated they are experienced as being out of character, unwanted and distressing. They generate considerable anxiety and are difficult to dismiss.

Obsessional doubts are common in OCD. These are the subjective feelings of doubt that a person has performed an action, even though they know deep down that he or she has done it. Repeating the action provides a temporary anxiety reducing effect.

The most common obsessions are:

• Fear of contamination (dirt, germs, viruses e.g. HIV, bodily fluids or faeces, chemicals, dangerous materials e.g. asbestos)
• Fear of harm coming to self (e.g. doors are not locked)
• Excessive concern with order or symmetry
• Obsession with the body or physical symptoms
• Religious, sacrilegious or blasphemous thoughts
• Sexual thoughts
• Fear of loss of objects or information which can lead to the urge to hoard useless or worn out possessions
• Thoughts of violence or aggression
• Perfectionism

Aggressive obsessions are common but are different from violent thoughts that occur in other psychiatric conditions such as Personality Disorders. People with OCD worry that they might commit an offence but do not carry out the feared act and spend an excessive amount of time resisting and controlling their behaviour to prevent this happening. They also find the thought extremely disturbing and abhorrent instead of the normal passivity of personality disorder.

Multiple obsessions are common, occurring in about 60% of people with OCD.

Compulsions are repetitive stereotyped behaviours or mental acts that the person feels driven to perform. A compulsion can either be overt and observable by others, such as checking that a door is locked, or a covert mental act that cannot be observed, such as repeating a specific phrase in the mind. They are not enjoyable and do not serve any useful purpose. They are often intended to neutralise anxiety provoked by the obsessions, but the relief is only temporary. Covert compulsions are generally more difficult to resist and monitor than overt ones as they can be performed without other people knowing and are easier to perform. The term “ritual” is synonymous with compulsion but usually refers to behaviours that other people can see.

The most common compulsions are:

• Cleaning
• Hand washing
• Checking (e.g. locks, gas taps)
• Counting
• Ordering and arranging
• Hoarding
• Asking for reassurance
• Needing to confess
• Repeating words silently
• Ruminations (uncontrollable prolonged thinking about the same subject)
• “Neutralising” thoughts (to counter the obsessional thoughts or images)

Compulsive slowness is recognised as a form of OCD where people may take several hours to do a task but may deny any obsessional thoughts. The motivation for the slowness is often to ensure that everything is performed perfectly. By aiming for perfection the person constantly fails and so they have to try harder which takes increasingly longer.

Multiple compulsions are common affecting about 50% of people.

Later in the course of OCD, rituals can become automatic and increase, rather than reduce the anxiety. This is because the rituals tend to prevent the person facing up to the anxiety generated by obsessions, and the person is therefore not able to confirm that their fears are groundless.

To qualify for the diagnosis the symptoms must be disabling.

The diagram above illustrates the obsessive compulsive disorder cycle.

Conditions that commonly occur with OCD include depression, Generalised Anxiety Disorder, specific phobias, social phobia, eating disorder, alcohol dependence, schizophrenia, panic disorder and Tourette’s syndrome. People suffering from developmental disorders such as autism or Asperger’s Syndrome may also present with obsessions. In these cases there is often an insidious onset of OCD at a young age and more frequent obsessions and compulsions concerning symmetry and perfectionism.

There is a strong association between OCD and depression, with a lifetime prevalence of depression in OCD sufferers of up to 70%. Depression may precede OCD. If the onset of OCD is preceded by depression, treatment of the depression may improve the symptoms of OCD. Depression however is more frequently a consequence of OCD. Unhappiness is an understandable consequence of the constant mental effort required to combat anxiety generated by the obsessions together with restriction on home, work and social life imposed by the compulsions.

About 20% of people with OCD also meet the diagnostic criteria for Generalised Anxiety Disorder (GAD). The presence of GAD is associated with excessive worries, indecisiveness and pathological concerns of responsibility. Some sufferers of OCD exhibit excessive health concerns. These people tend to have a poorer insight into the irrationality of their obsessions and a higher prevalence of GAD.

People with OCD maintain contact with reality and have insight into their condition. However, some people with OCD have “overvalued” ideas. These are ideas that the person has difficulty in recognising as being senseless. Because overvalued ideas are more difficult to challenge, people with these may respond less well to treatment.

It has been suggested that OCD symptoms may also represent a defence against the anxiety symptoms of an acute psychotic breakdown and a small number of people presenting with OCD later develop schizophrenia. People with Tourette’s syndrome present with tics (sudden involuntary twitching of muscle groups), grunts and obscene vocalisations and gestures. These may be mistaken for compulsive rituals but also many people with Tourettes do also have OCD symptoms and these can often be helped by treatment of the OCD.

Obsessive Compulsive Spectrum Disorders refer to a group of conditions characterised by intrusive thoughts or repetitive behaviour. These include:

Somatoform disorders (Hypochondriasis, Body dysmorphic disorder)

Eating disorders, Impulsive Personality Disorders (Antisocial and Borderline)

Impulse control disorders (Intermittent explosive disorder, pathological gambling, trichotillomania, sexual compulsions, kleptomania and compulsive buying).

Anankastic or Obsessional Personality Disorder (OCPD) leads to excessive conscientiousness; checking; stubbornness and caution; combined with perfection, pedantry and meticulous accuracy. These traits are often common in high achievers and over represented in certain careers (medicine, law, accountancy, insurance and the media). The difference between Obsessional Personality Disorder and OCD is that OCD sufferers are distressed by their condition whereas people with Obsessional Personality Disorders are not. There is little evidence to suggest that OCPD or obsessional traits are either a precursor to or associated with OCD.

A diagnosis of OCD is made when the traits are out of the person’s control leading to distressing and persistent obsessional thoughts and compulsive rituals and impaired functioning at home or work.

Amended June 2008