Obsessive compulsive disorder
In the first of our new mental health series, consultant psychiatrist Dr John Wilkins describes ways in which GPs can identify and manage patients with OCD
Obsessive compulsive disorder (OCD) is common, and every GP is likely to have patients who suffer from it. Prevalence rates from community studies vary but approximately one in 100 people have OCD, which means a GP with a list of 1,800 patients will have 18 sufferers on it. This rate seems to be independent of cultural factors.
OCD can start at any age from pre-school through to adulthood, but generally the symptoms begin by the age of 40. It usually starts earlier in men than women. Severity ranges from mildly inconvenient to totally incapacitating: about 20 per cent of those afflicted cannot lead normal lives. The cardinal features of the illness are obsessive ruminations and associated behavioural rituals that the patient knows are irrational, yet are irresistible. There may be a mixture of different obsessions and compulsions or one may predominate. Symptoms are often related to alterations in mood, often being more severe when patients are depressed. If they suspect a patient may have OCD, GPs can usually identify the condition by asking a series of questions (see box below right).Today, at least 75 per cent of patients can be treated to the point of being free of significant symptoms or improved sufficiently to be able to lead normal lives, but improvements are often not sustained when treatment finishes.It is important to help the patient accept they have a fairly common illness that can be treated and that they can discuss their symptoms openly without fear of shame or ridicule, which is usually a great relief.
Patients often have an initial preference for either medication, psychological therapy or both. Which treatments patients receive depends on availability. With long NHS waiting lists for psychological therapies, most patients are initially prepared to try medi- cation, unless psychological therapy is quickly available.
It would be sensible for the GP to initiate treatment with an SSRI while the patient is waiting for specialist assessment. This would be particularly so if there are significant symptoms of comorbid depression which there often are.It is desirable to see the patient regularly and, if the patient is willing, it can be helpful to involve a supportive partner or family member in the treatment plan, which would include an explanation of the illness and the purpose of the medication, plus information on the advocate group OCD Action (see useful websites above right). Large studies have shown more than 75% of patients are helped by medication that reduces both the frequency and intensity of their obsessions and compulsions. SSRIs are effective in the treatment of OCD and are usually the first choice due to their tolerability and safety. Sertraline, paroxetine and fluoxetine are generally thought to have a favourable risk-benefit ratio allied with long-term safety and tolerability. But they have to be prescribed at higher doses than those usually used in depression (see box far right).
Clomipramine, a combined SSRI and nor-adrenaline re-uptake inhibitor, was the first medication proven to be effective for OCD in the 1970s. Today, many still view it as the gold standard, particularly for resistant cases.
There is increasing evidence that atypical antipsychotic agents such as risperidone, olanzapine and quetiapine augment treatment responses. Selection depends on the side-effect profile and how well an individual drug is tolerated. If a patient responds to medication there will be an improvement of their obsessions, compulsions and mood. Long-term treatment protects against relapse, which is common when patients stop treatment. Many patients are successfully treated with just cognitive behaviour therapy, which is the only psychological therapy for OCD with an evidence base. Formal, non-directive counselling is not an appropriate treatment for patients with OCD and, in fact, is generally a waste of time and resources. Treatment requires modification of the beliefs that lead to the misinterpretation of the obsessional thoughts and of the compulsive or avoidant behaviours that maintain these beliefs.Therapy helps the OCD sufferer construct a new and less fearful attitude to their symptoms. The patient will be required to engage in diary keeping and homework that will include exposure tasks. CBT has been shown to be as effective as SSRIs, but there can be up to a 25% drop-out rate from treatment and other patients may not respond despite a commitment to therapy.It generally takes between 10 and 20 hours of treatment by a skilled therapist for a patient to become symptom-free. Contrary to popular belief, drop-out from psychological treatments is common despite apparent patient preference for such approaches. There are, however, several common pitfalls in treatment of OCD. These include:
• Patients with OCD may be very anxious about discussing their symptoms, particularly if they include thoughts of harming someone or sexual themes. It may be appropriate for the GP to ask for specialist help to clarify the diagnosis.• Providing ongoing support as part of a treatment plan is important as patients can have a difficult time with this illness. With severe anxiety, hopelessness, sleep problems and feelings of 'desperateness' and 'mental torture' in the clinical presentation, there may be an indication for short-term treatment with benzodiazepines or treatment with other agents such as pregabalin.
Patients who fail to respond to treatment in primary care should be referred to a psychiatric consultant at a hospital where they can receive specialist treatment. Where appropriate, GPs can manage pharmaco-therapy and refer directly to a clinical psychologist for CBT.
Dr John Wilkins is consultant psychiatrist, the Priory Hospital, Roehampton, and consultant psychiatrist, the Windsor and Maidenhead Early Intervention Team
Questions to ask a patient with suspected OCD• Do you wash or clean a lot?• Do you check things a lot?• Are there any thoughts that regularly upset you and that you would like to stop but can't?• Do your daily rituals take a lot of time?• Are orderliness and symmetry important to you?
Judging SSRI dosesPatients with OCD respond very differently to SSRIs from patients with depression. Neither the dosage nor the timetable for depression will be effective for OCD. • The dose for OCD must be significantly higher – say 80mg of fluoxetine daily • Maximum response will not be reached for 12 to 16 weeks