The difference between I-CBT and standard CBT 

Standard CBT treatment for OCD is based on the idea that obsessions find their origin in random intrusive cognitions, which develop into obsessions depending on how the person interprets them. For example, a person with a random intrusive thought about harming someone will develop obsessions only if these thoughts are negatively interpreted. Consequently, standard CBT is focused on helping clients to no longer
mis-appraise or negatively react to these thoughts. It does not really address the initials thoughts preceding the appraisal (the doubts).

I-CBT takes a different approach to CBT. While intrusive thoughts are normal, and they occasionally occur to everyone, obsessions are not viewed as originating from  random intrusive thoughts. Instead, I-CBT views obsessions are as inferences or doubts that come about due to prior reasoning.

I-CBT is based on the central idea that obsessions are abnormal doubts about what “could be”, or “might be” (e.g. “I might have left the oven on”; “I might be contaminated”; “I might be a deviant”). According to I-CBT, obsessional doubts do not come out of the blue, but they arise as the result of a dysfunctional reasoning narrative that is characterized by distrusting the senses and an over-reliance on the imagination. As a result, obsessional doubts are able to persist without ever being fully resolved by carrying out compulsions. I-CBT aims to bring resolution to
obsessional doubts before they reach the compulsion stage in the OCD cycle.

Another important feature of I-CBT is that it does not include deliberate or prolonged exposure and response prevention (ERP). While ERP can be effective technique, not everyone can tolerate the distress caused by it, nor does everyone benefit from it.

I-CBT is a far more cognitive approach. It is specifically focused on the obsession and where it comes from so that obsessional doubt is resolved naturally without any effort. I-CBT does include some behavioural exercises, but these focus on trusting reality without experiencing anxiety.

Why I-CBT might be a better alternative to CBT

There is substantial clinical trial evidence that has demonstrated I-CBT to be an effective treatment for the majority of those suffering from OCD. And because of the success my patients have achieved with this treatment protocol in my own practice, I can wholeheartedly recommend this approach. It would certainly be my first choice especially for more cognitive manifestations of OCD (eg “pure O types”. In addition, it
can be especially useful for those who are unwilling to tolerate ERP in traditional CBT, and for those who have previously been unable to benefit from other treatments.