Answers

Short answers

1 The patient has obsessive compulsive disorder.

2 The prevalence of obsessive compulsive disorder in the UK is between 1% and 3%.

3 Selective serotonin reuptake inhibitors or clomipramine are the best types of medication to treat this disorder.

4 The National Institute for Health and Clinical Excellence recommends cognitive behavioural therapy, including exposure and response prevention, for patients with obsessive compulsive disorder.

Long answers
1 Obsessive compulsive disorder
Obsessive compulsive disorder is a serious anxiety disorder characterised by repetitive, intrusive, and unwelcome thoughts, images, impulses, and doubts and usually by physical or mental behaviours carried out to reduce the anxiety associated with the obsessions. The case patient does not have hallucinations or delusions—she is aware that her thoughts, fears, and impulses are products of her own mind and that they are ego-dystonic (that is, out of keeping with her rational beliefs and wishes). Her recurrent thoughts and impulses are experienced as intrusive and inappropriate and cause her distress. She tries to suppress or neutralise them with other thoughts and actions, such as the chanting of formulae. These behaviours are compulsions—they are not connected in a realistic way with what they are designed to neutralise or prevent and, in this case, of blocking windows, are clearly excessive. When obsessive compulsive disorder results in extreme avoidance (in this case avoidance of the tower block), the obsessions and compulsions temporarily remit but the avoidance also grows.

2 Prevalence
Between 1% and 3% of the UK population have obsessive compulsive disorder, with females slightly more likely to be affected than males. It is probable that there are many undiagnosed sufferers however as the condition is usually kept secret for many years before presentation. The obsessions or compulsions are often not realised to be pathological in milder cases and in children, as the disorder is associated with a spectrum of symptoms that blur into normal experience.

3 Pharmacological treatment
Selective serotonin reuptake inhibitors or clomipramine are the best types of medication to treat obsessive compulsive disorder. The selective serotonin reuptake inhibitors fluoxetine (in adults) and sertraline (for under 18s) are regarded as first line treatments given that they have a safer side effect profile than clomipramine. The dose of selective serotonin reuptake inhibitor used needs to be considerably higher than that used to treat depression: 60 mg fluoxetine for obsessive compulsive disorder compared with 20 mg for depression. Clomipramine was the first drug treatment found to be effective for obsessive compulsive disorder. This agent is still used in treatment resistant obsessive compulsive disorder that has not responded to newer drugs or where they are not tolerated by the patient.

4 Other treatments
Cognitive behavioural therapy, including exposure and response prevention, is the optimum psychotherapeutic treatment for obsessive compulsive disorder. The National Institute for Health and Clinical Excellence recommends this approach as the treatment of choice, at least in the first instance, for patients with mild obsessive compulsive disorder.¹ In practice, many patients with a more severe variant of the disorder will need both psychological and pharmacological approaches. Interestingly, patients who flourish without formal cognitive behavioural therapy might do so because they are conducting their own informal exposure programme in everyday life. Medication has a higher rate of relapse on discontinuation than does cognitive behavioural therapy.

Cite this as: BMJ 2009;339:b2639