Imagine you are getting up in the morning. You know you will need to go to the bathroom, but the thought of accidentally touching the doorknob is frightening. There may be dangerous bacteria on it. Of course you cleaned the entire bathroom yesterday, including the usual series of spraying disinfectant, washing and rinsing. As usual it took a couple of hours to do it the right way. Even then you weren’t sure whether you had missed an area, so you had to re-wash the floor. Naturally the doorknob was sprayed and rubbed three times with a bactericidal spray. Now the thought that you could have missed a spot on the door knob makes you very nervous.

This description might give you some sense of the tormented and anxious world that people with Obsessive Compulsive Disorder (OCD) live in. It is a world filled with dangers from outside and from within. Often elaborate rituals and thoughts are used to ward off feared events, but no amount of mental or physical activity seems adequate, so doubt and anxiety are often present.

People who do not have OCD may perform behaviours in a ritualistic way, repeating, checking, or washing things out of habit or concern. Generally this is done without much, if any, worry. What distinguishes OCD as a psychiatric disorder is that the experience of obsessions, and the performance of rituals, reaches such an intensity or frequency that it causes significant psychological distress and interferes in a significant way with psycho-social functioning. The guideline of at least one hour spent on symptoms per day is often used as a measure of ‘significant interference’. However, among patients who try to avoid situations that bring on anxiety and compulsions, the actual symptoms may not consume an hour. Yet their situations would dearly constitute interfering with functioning. Consider, for instance, a welfare mother who throws out more than $100 of groceries a week because of contamination fears. Although this behaviour has a major effect on her functioning, it might not consume one hour per day.

Patients with OCD describe their experience as having thoughts (obsessions) that they associate with some danger. The sufferer generally recognises that it is his or her own thoughts, rather than something imposed by someone else (as in some paranoid schizophrenic patients). However, the disturbing thoughts cannot be dismissed, and simply nag at the sufferer. Something must then be done to relieve the danger and mitigate the fear. This leads to actions and thoughts that are intended to neutralise the danger. These are the compulsions. Because these behaviours seem to give the otherwise ‘helplessly anxious’ person something to combat the danger, they are temporarily reassuring. However, since the ‘danger’ is typically irrational or imaginary, it simply returns, thereby triggering another cycle of the briefly reassuring compulsions. From the standpoint of classic conditioning, this pattern of painful obsession followed by temporarily reassuring compulsion eventually produces an intensely ingrained habit. It is rare to see obsessions without compulsions.