Obsessive Compulsive Disorder

OCD can be treated by pharmacotherapy and/or behavioural therapy. A combination of these two therapies is an effective method of treatment for most people.

Drug therapy

Antidepressant medication is commonly prescribed irrespective of co-existing depression. 8 to 16 weeks are usually needed for maximal therapeutic response. Clomipramine, a tricyclic antidepressant (TCA) used to be the usual treatment. Of all the tricyclic and tetracyclic drugs, clomipramine is the most selective for serotonin reuptake versus norepinephrine reuptake and is exceeded in this respect only by the SSRIs especially sertraline and paroxetine. However TCAs have more side effects than the newer Selective Serotonin reuptake inhibitors (SSRI's). Therefore initially in most cases now, SSRI’s are prescribed because of the improved safety, tolerability, and equivalent effectiveness. It is usual to take medication for at least a year. The doses needed to treat OCD are sometimes higher than those needed to treat depression. Symptoms can improve by up to 60% with medication. SRIs are more likely to be helpful for pathological doubt, aggressive obsessions and urges, and mental rituals than for slowness, hoarding, and tic-like symptoms.

Behavioural Therapy

Behaviour therapies have been proved to be as efficacious in treatment of OCD as the pharmacotherapy with one added advantage. Behaviour therapy provides better relapse prevention and the beneficial effects are longer lasting. Therefore many clinicians consider behavioural therapies to be treatment of choice. The principal behavioural approach is Exposure and Response prevention (ERP). Other approaches like desensitisation, thought stopping, implosion therapy, flooding and aversive conditioning are second line approaches in behavioural therapies. In younger patients, experts are more likely to use behavioural therapy alone.

Exposure and relapse prevention can be used with cognitive therapy which involves exploring the nature of anxiety and stress responses. The therapist will then gradually expose the individual to the feared object or idea, either directly or by imagination, and then discourages or prevents them from carrying out the usual compulsive response. The aim is for the individual to gradually experience less anxiety from the obsessive thoughts and become able to forgo the compulsive actions for extended periods of time.

For a patient with predominance of compulsive symptoms, exposure and relapse prevention is the treatment of choice in all behavioural therapies. For patients with predominance of obsessive symptoms, either exposure and relapse therapy or a combination with cognitive therapy can be used as first line treatment.Cognitive therapy may be more useful for pathological doubt, aggressive obsessions, and scrupulosity or other "OCD beliefs" as contrasted to "urge" like symptoms such as arranging or touching rituals. Habit reversal, which depends primarily on establishing a set of competing responses, may be especially useful for tic-like compulsions. Desensitisation is always the second line in both the cases.

REFERENCES:

1. Kaplan and Saddock synopsis of psychiatry, 622-623, Ninth Edition
2. Guidelines for treatment of OCD, John S. March, MD, MPH; Allen Frances, MD; Daniel Carpenter, PhD; David A. Kahn, MD

Category: Psychiatry Notes