A look at the Science - Obsessive Compulsive Disorder

A look at the Science - Obsessive Compulsive Disorder

Note: This article is a review of the scientific literature about OCD. It is quite detailed and was originally an article for one of my university courses, you may however find it interesting. It is not meant as a diagnostic tool of course, this is just research I have done. It has been marked and found to be accurate by my professor. 

Obsessive Compulsive Disorder (OCD) is an anxiety disorder defined by the presence of obsessions, compulsions or most often, both. Obsessions are characterised by repetitive and persistent thoughts and images which are intrusive in nature and cause significant anxiety or distress. These thoughts and images are then neutralised or supressed by compulsions to decrease the anxiety and distress that accompanies these obsessions. Compulsions can include repetitive behaviours and thoughts. Often these obsessions and compulsions are not connected in a direct way (American Psychiatric Association, 2013).

Cognitive behavioural models can be used to explain the development and maintenance of OCD as well as assisting in developing methods of treatment. There are three main aspects of OCD which can be accounted for by cognitive models. These are the presence of obsessions, a reaction to these thoughts and images that is one of repulsion, distress and anxiety as well as an effort to ignore, avoid, neutralise or repress these thoughts through compulsive behaviours and/or mental rituals (Abramowitz, & Houts, 2005). Fundamental to understanding OCD is that these intrusive thoughts occur in the normal population, however it is the negative appraisals of these common thoughts that leads to an increase in the intensity of these thoughts and thus the development and maintenance of OCD (Clark, Purdon, & Wang, 2003).

Purdon and Clark’s Cognitive theory is one which seeks to model how OCD is developed and maintained. This model has two key elements – that one sees a need to be in control of their thoughts and places much importance on this and that being unable to control these intrusive thoughts is negatively interpreted. This contributes to the maintenance of these ego-dystonic obsessions (Purdon & Clark, 2002). These negative appraisals of intrusive thoughts result in a need to control and resist them (Abramowitz, & Houts, 2005). Failure to do so however results in increasing intensity of these thoughts as well as reinforcing negative schema about one’s true self, for instance, “If I keep thinking these thoughts and cannot control them then I must be a truly awful person”. The inability to supress intrusive thoughts leads to more personal significance being placed on obsessions, leading to maintenance of these obsessions. This can be contrasted to the worrying seen in generalised anxiety disorder whereby one does not feel a need to control and supress thoughts to the same degree as they are more ego-syntonic than in OCD where the obsessions are ego-dystonic (not in line or repugnant to one’s self-image).

This cognitive theory has been similarly supported by Rachman (1998). Obsessions occur as a result of one catastrophizing and misinterpreting thoughts which occur in the normal population. This misinterpretation and significance placed on the obsessions, ie. Labelling them as bad or immoral allows them to perpetuate. A significant aspect of this model is thought-action fusion, meaning that one interprets their thoughts as equivalent to actions. For instance, “If I think about someone becoming sick, then they might and it will be because of me” or from a moral standpoint “If I think about running someone over with my car this is as bad as actually doing it”.  (Rachman, 1998). Furthermore, this theory provides explanation as to how OCD is maintained. Attempts at suppressing thoughts as well the frequency of obsessions can be used by individuals as evidence for their importance, threat and the responsibility they have over their thoughts.

It is widely accepted that psychological management is efficacious in the treatment of OCD. The 2 main treatment models which are used are cognitive behavioural therapy (CBT) and exposure and response prevention (ERP). CBT is based on the cognitive model of OCD development, and treatment focuses on the therapist cognitively challenging the individual’s errant intrusive thoughts and replacing them with more adaptive interpretations. ERP exposes participants to perceived threat and conditions participant not to respond to threat with a compulsive activity. For this treatment to be effective, a person’s reaction to intrusive thoughts, ie. seeing them as distressing must be changed in addition to removing compulsive behaviours and mental acts which reduce the anxiety (Abramowitz, & Houts, 2005). ERP involves a person being exposed to a distressing situation or imagining this situation which will trigger obsessional thoughts without completing a compulsion. The aim of ERP is to remove the conditioned fear response which has arisen accompanying the obsessions by repeated exposure, reducing dysfunctional beliefs (excessive responsibility, the need to control thoughts and placing importance on thoughts simply because they happened) and to learn to manage feared obsessions without the need for compulsive behaviours to neutralise the threat (Abramowitz, 2006).

Both ERP and CBT have been shown to be superior to no treatment, however expert opinion would suggest ERP is the currently viewed as the most effective treatment for OCD (Taylor, Abramowitz & McKay, 2008, Franklin & Foa, 2002). A study into group treatment of OCD comparing ERP to CBT, ‘Cognitive Versus Behaviour Therapy in the Group Treatment of Obsessive-Compulsive Disorder’ McLean et al 2001, found ERP to be more efficacious despite both treatment groups faring better than the control. Groups of patients were randomised to CBT, ERP or waitlist comparison, the waitlist group were later treated. Both CBT and ERP were found to be superior to waitlist management and subsequent treatment of the waitlist reinforced these results. In a study, ‘Treatment of obsessive–compulsive disorder: Cognitive behaviour therapy vs. exposure and response prevention’, Whittal et al 2003, studied two groups of patients treated with individual treatment with CBT or ERP and concluded that there was a clinical, but not statistical benefit in the CBT group vs ERP group. The authors postulated that intrusive thoughts may be more likely to be disclosed and challenged in an individual setting than in a group. This study has been criticised though as it had a shorter treatment and follow up period than other studies. However, a meta-analysis conducted in 2005, ‘How effective are cognitive and behavioural treatments for obsessive–compulsive disorder? A clinical significance analysis’ (Fisher, & Wells, 2005) concluded that ERP was the superior psychological treatment for OCD contrary to the research performed by Whittal et al. This study standardised treatment outcomes and included studies that were representative of patients seen in routine practice, making it potentially more transferable to real life conditions. They concluded ERP was more efficacious, but that it needed to be delivered in an appropriate format, ie. Long sessions of exposure (90 minutes), 15-20 sessions to achieve recovered status according to the Yale-Brown Obsessive Compulsive Scale (Franklin & Foa, 2002).

OCD is a disorder affecting approximately 1.2% of the population which consists most commonly of two aspects – obsessive intrusive thoughts and compulsive actions or mental acts to reduce distress accompanying these thoughts. Through the development of cognitive models the way in which OCD is developed and maintained can be understood and methods of treatment developed. The most efficacious treatment is ERP; however, it must be delivered over an extended period of time with sessions of exposure between 60-90 minutes long for it to be effective.

Any information on this blog is not a substitute for professional advice. It is written from personal experience and research only. If you are in crisis, go to your nearest emergency room, call lifeline on 13 11 14 or dial 000. If you live outside Australia, link to worldwide crisis numbers can be found in the sidebar.

Reference List:

Abramowitz, J. (2006). The Psychological Treatment of Obsessive-Compulsive Disorder. Canadian Journal of Psychiatry51(7), 407-415.

Abramowitz, J., & Houts, A. (2010). Concepts and controversies in obsessive-compulsive disorder (1st ed., pp. 229-260). New York: Springer.

Abramowitz, J., McKay, D., & Taylor, S. (2008). Obsessive-compulsive disorder (1st ed.). Amsterdam: Elsevier.

American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders (5th ed.). United States.

Clark, D., Purdon, C., & Wang, A. (2003). The Meta-Cognitive Beliefs Questionnaire: development of a measure of obsessional beliefs. Behaviour Research and Therapy41(6), 655-669.

Fisher, P., & Wells, A. (2005). How effective are cognitive and behavioural treatments for obsessive–compulsive disorder? A clinical significance analysis. Behaviour Research and Therapy43(12), 1543-1558.

Franklin, M., & Foa, E. (2002). Cognitive behavioural treatments for obsessive compulsive disorder. A Guide to Treatments that Work, 367-386.

McLean, P., Whittal, M., Thordarson, D., Taylor, S., Söchting, I., & Koch, W. (2001). Cognitive Versus Behaviour Therapy in Treatment of Obsessive-Compulsive Disorder. Journal of Consulting and Clinical Psychology69(2), 205-214.

Purdon, C., & Clark, D. A. (2002). Mental control beliefs and appraisals in OCD. In R. O. Frost & G. Steketee (Eds.), Cognitive approaches to obsessions and compulsions: Theory, assessment and treatment (pp. 29–43). Oxford: Elsevier.

Rachman, S. (1998). A cognitive theory of obsessions: Elaborations. Behaviour Research and Therapy, 36, 385–401.

Rassin, E., Diepstraten, P., Merckelbach, H., & Muris, P. (2001a). Thought–action fusion and thought suppression in Obsessive-Compulsive Disorder. Behaviour Research and Therapy, 39, 757–764.

Whittal, M., Thordarson, D., & McLean, P. (2005). Treatment of obsessive–compulsive disorder: Cognitive behaviour therapy vs. exposure and response prevention. Behaviour Research and Therapy, 43(12), 1559-1576.

What not to say.

What not to say.

OCD and me. What it's like in my brain.

OCD and me. What it's like in my brain.