Discuss how you would assess, and come to a decision about therapy for a patient who presents with OCD.

• Obsessive compulsive disorder (OCD) is a not uncommon illness which is characterized by thoughts that recur despite being unwanted, and/ or acts which the person feels compelled to carry out.
• In thinking about treatment, it is important to understand the psychopathology of obsessive ideas and compulsions. They generally have the following characteristics:

1. They are recognized as originating from within, and are not interpreted as alien or external.
2. There must be at least one thought or act that the person attempts to resist. In general, it is the repetition of the thought or act that is resisted, not the thought or act itself.
3. The repetition of the thoughts or acts is ego-dystonic - i.e. unwanted and unpleasurable.
4. The thoughts or acts are carried out in an attempt to reduce anxiety.

• Many people will describe an anxiety-provoked checking of lights, doors, etc. and to a large extent these are due to what could be called 'obsessional' personality traits. OCD only becomes a disorder when it interferes significantly with social functioning. For example, if someone cannot leave the house because of a ritualistic handwashing that must be carried out repeatedly, then the effect on social function can be seen quite clearly.

• According to the ECA study, OCD has a lifetime prevalence of around 2-3%, higher than initial estimates. It affects males as frequently as females. Its mean age of onset is around 20 years old, but studies have shown that it takes up to 7-8 years for someone to present to the psychiatric services (Rasmusen and Tsuang, 1986). It is easy to postulate the degree of disability during this time.

• The characteristics of obsessions and compulsions are described above. Probably the most common presenting symptoms are obsessive doubts and concomitant compulsive checking (e.g. did I leave the door unlocked?), and obsessive fears of contamination with compulsive washing. Other symptoms include obsessional images (often violent or sexually obscene), compulsive counting, and obsessional slowness. Obsessions about cleanliness tend to be more common in females, whereas obsessional slowness is more common in men.
• Comorbid conditions such as depression are relatively common, and the suicide rate is increased, even when a depressive illness is controlled for

• By understanding what causes an illness, we are better able to treat it. Therefore it is necessary to look at current understandings of the causes of OCD.

Genetic:

• there is evidence of a genetic basis in the much higher MZ:DZ twin ratios
• Tourette's syndrome, a tic disorder, is also characterized by obsessional thoughts and compulsive rituals, and many of those (up to 20%) with OCD also have tics, suggesting a common aetiology perhaps
• 35% of 1^st degree relatives of probands with OCD also have the disorder

Biochemical:

• it has been proposed that OCD is to some extent due to a dysregulation of serotonin (5-HT) neurotransmission. There are abnormal responses to MCPP (5-HT agonist/ antagonist) suggesting that 5-HT function is abnormal in OCD.
• The condition also responds to drugs such as the serotonin uptake inhibitors, supporting the idea that 5-HT may be abnormal.

Neurological:

• With the advent of improved neuroimaging, a better understanding of the brain pathways responsible has been gained.
• PET scanning has revealed abnormal blood flow in the orbitofrontal cortex, caudate nucleus, and cingulate gyrus. It is possible that an abnormal circuit involving at least these three structures is partly responsible for some of the psychopathology of OCD. With effective treatment, these abnormalities normalize.

Psychological and psychoanalytical theories:

• Psychoanalysts would propose that the symptoms in OCD are generated by attempts to defend against conflicting drives and desires. Defense mechanisms involved include reaction formation, undoing, magical thinking, and isolation.
• Behavioural psychologists see OCD as being due to abnormal learnt behaviours and that obsessions are conditioned stimuli, and compulsions are avoidance strategies to reduce anxiety.

• Treatment can be divided into three different headings: pharmacological, psychological, and other. The most effective method is to combine the first two approaches, but we will look at each form of treatment in turn

• The first effective pharmacological treatment for OCD was Clomipramine, whose antiobsessional properties were noted in 1967. There is an impressive body of placebo-controlled trials since then which have pretty much all supported the effectiveness of Clomipramine. The antiobsessional qualities are independent of the antidepressant properties, and the best antiobsessional drugs are those with serotonergic activity.
• Perhaps the most commonly-used drugs are the SSRIs, which tend to be better tolerated than Clomipramine. Large placebo-controlled trials have shown the effectiveness of fluoxetine, paroxetine, fluvoxamine, and sertraline in treating OCD.
• Is clomipramine better than the SSRIs? There are some meta-analyses that would suggest that clomipramine is more potent that the SSRIs, but it is possible that the initial studies of clomipramine included more severe patients who could be expected to have a greater improvement with treatment, and lower response to placebo.
• More and more evidence is emerging supporting the long-term treatment of OCD with drugs. These drugs are effective in 60-80% of patients, but relapse rates are high when the drugs are discontinued, especially if they had not been combined with behavioural methods. Studies have shown that the response to SSRIs is maintained if medication is continued (Katz, 1990).

• Most of these approaches are based on the idea that OCD is a problem of learnt maladaptive behaviours.
• A treatment approach to OCD would involve:

1. behavioural assessment (mapping) - involves creating a hierarchy of obsessions and compulsions, with treatment first tackling the least troublesome situations.

• The most widely used approach to OCD is exposure combined with response prevention. Patients are helped to expose themselves to those distressing activities or situations which they avoid, and then to resist the compulsions. The individual is forced to experience and learn to tolerate the discomfort of the feared situation without the relief of anxiety-reduction rituals. It is thought that the anxiety response habituates.
• It is recognized that behavioural approaches to OCD are more effective for compulsions than for pure obsessions, which are found in 2% of patients. For these patients, 'thought stopping' may be helpful. This involves a command which is used to terminate an unwanted thought.

• OCD can be a relentless condition which fails to respond to the 1^st line therapies available. Other possibilities include:
• augmenting the SSRI with a neuroleptic — this is most effective for those people with OCD and tics
• lithium may be tried in non-responders, but the only double-blind RCT of lithium and antidepressant did not find it effective
• fenfluramine in combination with SSRIs has been associated with improvements in some open case studies
• other possible combination therapies include:
• buspirone
• tryptophan
• thyroid supplementation
• MAOIs
• clonazepam
• for some intractable cases, psychosurgery can be considered. Between 40-60% of patients show benefit. The operations in current use include:
• anterior cingulotomy
• subcaudate tractotomy
• limbic leucotomy
• anterior capsulotomy

• We have seen that OCD is a relatively common condition which can result in significant morbidity in terms of social functioning. Its effects on the process of everyday life mean that depression is often comorbid, and other common sequelae include reduced self-esteem, impaired interpersonal relationships, affected employment.
• Our understanding of this condition has resulted in a number of effective treatments, the most effective of which is probably behavioural psychotherapy combined with serotonergic antidepressant therapy, continued long-term.
• The choice of therapy will be a combination of individual preference and local availability of treatments. About 25% of patients refuse behavioural treatment, and a similar proportion refuse medication. A good relationship with the patient and an open discussion of possible therapeutic options is likely to result in the best available treatment for the patient.