Prognosis and duration of disabling effects

Obsessive Compulsive Disorder (OCD) may follow an acute, episodic, chronic unremitting, deteriorating or relapsing course. For some people the symptom type will remain unchanged, but for others the symptoms change over time. Intermittent, episodic disorder is more common in the early stages of the disorder whereas chronic illness is more common in the later stages.

The response to treatment is usually good. For example, Exposure and Response Prevention (ERP) has response rates of up to 85% in people who complete the treatment, but this may take several months. The response to drug treatment increases gradually over weeks and months and the benefits continue to accrue for at least six months and have been shown for up to 2 years. Resistant cases that require different types of treatment may take a year or more to achieve functional improvement.

A recent study of people with severe OCD showed that 6 to 8 years after treatment, approximately:

• 27% no longer met the criteria for the diagnosis of OCD (i.e. were effectively “cured”)
• 17% had mild symptoms
• 34% had moderate symptoms
• 24% had severe symptoms

Worse outcome was associated with longer duration of illness before treatment.

Therefore for people who are undergoing treatment, a short term award of 2 years is recommended, in order to give time to assess the response to treatment.

For people who have received treatment but have responded poorly, a longer term award of 10 years is recommended, as it is possible that further treatments may be instituted in the future.

All information must be taken into account when considering the duration of disabling effects and the duration of disabling effects must be based on the particular circumstances of the individual claimant.

Amended June 2008