The Psychology of OCD

Why do some people develop debilitating obsessions and compulsions?

Posted Dec 03, 2019

On one occasion during the 1970s, when psychologists had just begun detailed research on obsessions and compulsions, a decision was made to hospitalize a participant with severe obsessive checking problems, so that the researchers could measure and assess his multiple checking rituals in a controlled environment. To their surprise, once he’d been admitted to the hospital, most of his checking behaviors disappeared, and he readily and without anxiety began to involve himself quite normally in the daily life of the ward.

At first, it wasn’t obvious what had caused this sudden and dramatic loss of symptoms—perhaps it was a miraculous, spontaneous recovery. But as soon as he returned home, all of the old rituals reappeared as severely as ever. Quite soon, it became apparent what was happening, and this insight cast light on one of the most significant psychological factors that cause and maintain behaviors, such as compulsive checking and compulsive washing.

Many compulsions are enacted because the sufferer believes this will prevent something bad from happening. Checking the stove is off prevents a potential gas explosion, checking the doors and windows are locked prevents the house from being burgled, washing one's hands until they are raw prevents contamination and the possible spread of diseases to others. These activities confer on the checker and the washer a significant responsibility for ensuring that these bad things don’t happen.

Not only do individuals with OCD tend to feel responsible for ensuring that bad things don’t happen, but they also have a highly inflated sense of responsibility that evokes guilt and shame at the possibility of bad things happening if their compulsive rituals are not completed properly and thoroughly[1]. OCD is a slow-onset disorder, but we can often trace the beginnings of obsessions and compulsions to either a stressful life event or a life change that bestows greater responsibilities on the individual, such as a new job, the birth of a child, or even puberty. Many people take their new responsibilities very seriously and develop inflated responsibility that generates anxiety and a driving desire to ensure that they don’t let themselves and others down by allowing bad things to happen.

Early studies of OCD often failed to get sufferers to indulge in their compulsions and rituals in the lab in the same way they would in other situations. It eventually became clear that while they were in the lab, these participants had transferred responsibility for any misfortunes happening to the experimenter, so there was significantly less need to indulge in their checking and washing behaviors [2]. This also appears to explain the behavior of our hospitalized patient in the opening paragraph—the hospitalization had led to the transfer of responsibility for any unfortunate outcomes to the hospital staff.

Inflated responsibility is one of the most significant cognitive characteristics underlying OCD. It’s why checkers check and why washers wash. But it’s also why those with obsessive thoughts find those thoughts aversive—because if they have intrusive thoughts about bad things (e.g., blasphemous behaviors if they’re religious, or thoughts about killing their own child), they believe they are fully responsible for having those thoughts (even though they probably have no voluntary control over intrusive thoughts such as these), and this evokes high levels of anxiety, guilt, and shame. CBT that targets inflated levels of responsibility and attempts to reduce feelings of responsibility results in significant therapeutic gains, often with a 50-100 percent reduction in OCD symptoms over a significant post-treatment period[3].

Now for something rather different. What gives a person the urge to murder another human being—a psychopathic personality, a grudge, an angry, impulsive action? Maybe, but Adam Shaw believes he’d kill someone with a thought. One day, he was passing through reception at an airport in Arizona and noticed the young receptionist at the desk.

“I’m going to strangle her,” he thought. “It must mean I’m going to do this. Therefore I’m dangerous; they’ll arrest me and put me in a mental hospital or prison. I can’t get the thought out of my head. It’s such an awful thought; it must mean I’m going to do it.”[4] 

No, Adam didn’t murder the receptionist; he’d come to believe that if he had a thought about something, it was the same as doing it. Adam is the founder of the mental health charity The Shaw Mind Foundation and co-author of Pulling the Trigger, which describes Adam’s lifelong struggle with OCD[5]. Adam’s belief that he could kill by just having a thought is known as thought-action fusion, and it’s a common characteristic of individuals who have developed OCD symptoms. It’s a belief that thoughts and actions are linked and that having an unacceptable thought can also influence the real world—effectively, it means that having a thought about an action is like doing the action.

Thought-action fusion is just another way in which appraising unwanted and intrusive thoughts as meaningful not only increases distress and feelings of responsibility, but it also increases the urge to neutralize and suppress unwanted thoughts. As you can imagine, thought-action fusion is found at significantly higher levels in individuals with OCD than in non-clinical samples[6]. It’s still not clear why some people exhibit thought-action fusion, and others don’t, but some studies suggest it may be related to personality traits such as magical thinking in which people hold strong beliefs in psychic phenomena (such as feeling that they can communicate telepathically with other people), and believe that some things can affect other things in ways as yet unknown to science[7].

But when it generates distressing OCD symptoms, thought-action fusion is a characteristic that can be successfully addressed by cognitive restructuring therapies. This helps sufferers to learn to recognize the irrationality of thought-action fusion and to respond to an irrational thought (“I may wander out into the road and cause an accident”) with a more rational and evidence-based thought (“I have had this thought many times, and never once have I wandered out into the road and caused an accident”).

For the next example, I want you to spend a few seconds imagining there’s a translucent green rabbit sitting on your head. Done it? Can you feel it sitting there? Can you visualize its greenness? Now focus on its fluffy, green, translucent ears. Right, next count to five, and when you’ve done that, I want you to spend the next 60 seconds not thinking in any way, shape, or form about a translucent, green rabbit that’s just been sitting on your head.

Did you find it difficult to suppress thoughts about the imaginary rabbit deliberately, and did you experience images of the rabbit spontaneously hopping into your stream of consciousness? That’s what research psychologist Dan Wegner has found. He asked participants in his experiments to try not to think of a white bear but found that after being given this instruction, they were unable to stop thinking of white bears[8]. It seems that attempted thought suppression has paradoxical effects as a self-control strategy, often producing the very obsession or preoccupation that it was directed against.

This finding has particular relevance for OCD when individuals deliberately attempt to control their aversive, intrusive thoughts by ignoring, neutralizing, or suppressing them. Clinical psychologist Paul Salkovskis has argued that unwanted, distressing thoughts may be converted into obsessions when active thought suppression ironically increases their frequency or causes their frequency to "rebound" after a period of suppression[9]. The perceived failure to suppress particular thoughts after a period of active attempts at suppression also has the effect of causing increased distress and anxiety[10]. It’s a process that has a significant effect on OCD symptoms for many people.

Finally, OCD is frequently known as the "doubting disease." People with OCD often claim that when they’re checking, washing, or systematically ordering objects in their environment, they’ll need to continue doing this, because things feel "not quite right." This is a doubting feeling that appears to drive their ritualistic compulsions to be completed fully and properly.

For many years, it was assumed that this doubting might be underpinned by some memory problems in OCD sufferers. But ironically, rather than memory deficits causing repeated checking, it’s repeated checking that appears to cause memory doubts. For example, individuals with OCD symptoms will spend a lot of time checking both relevant and irrelevant things on a daily basis, and this overloads executive processes in the brain and results in the poor encoding of information and poor attention to relevant information—both of which together will cause memory deficits[11]. In effect, the more that someone checks, the less confident they’ll be about what they’ve checked! So, paradoxically, one of the symptoms of OCD has become a cause of it, creating what may well be a vicious toxic cycle of doubting and ensuing checking[12].

These are some of the important psychological processes that give rise to OCD symptoms and frequently have to be addressed during treatment. Once again, we see that anxiety-based problems regularly revolve around distorted thinking and the way we each interpret our own thoughts[13]. It also illustrates the way that thoughts influence actions (such as feelings of responsibility generating complex compulsions), and actions also influence thoughts (the compulsions themselves can also generate doubting), and these relationships can often become cast in a vicious cycle that maintains our compulsive behaviors and obsessive thoughts.


[1] Salkovskis PM (1985) Obsessional-compulsive problems: A cognitive-behavioural analysis. Behaviour Research & Therapy, 23, 571-583.

[2] Röper G & Rachman S. (1976) Obsessional-compulsive checking: Experimental replication and development. Behaviour Research & Therapy, 14, 25-32.

[3] Ladouceur R, Léger E, Rheaume J & Dubé D. (1996) Correction of inflated responsibility in the treatment of obsessive-compulsive disorder. Behaviour Research & Therapy, 34, 767-774.

[4] http://www.ocduk.org/pulling-the-trigger-air-crash

[5] Shaw A & Callaghan L (2016) Pulling the trigger: OCD, anxiety, panic attacks and related depression – the definitive survival and recovery approach. Trigger Press.

[6] Rassin E, Merckelbach H, Muris P & Schmidt H (2001) The thought action fusion scale: Further evidence for its reliability and validity. Behaviour Research & Therapy, 39, 537-544.

[7] Lee H-J & Telch MJ (2005) Autogenous/reactive obsessions and their relationship with OCD symptoms and schizotypal personality features. Anxiety Disorders, 19, 793-805.

[8] Wegner DM, Schneider DJ, Carter SR III & White TL (1987) Paradoxical effects of thought suppression. Journal of Personality & Social Psychology, 53, 5-13.

[9] Salkovskis PM (1996) Cognitive-behavioral approaches to understanding obsessional problems. In RM Rapee (Ed) Current controversies in the anxiety disorders. Guilford.

[10] Purdon C, Rowa K & Antony MM (2005) Thought suppression and its effects on thought frequency, appraisal and mood state in individuals with obsessive-compulsive disorder. Behaviour Research & Therapy, 43, 93-108.

[11] Harkin, B. & Kessler, K. (2011). The role of working memory in compulsive checking and OCD: A systematic classification of 58 experimental findings. Clinical Psychology Review, 31, 1004–1021.

[12] Van den Hout, M. & Kindt, M. (2003). Phenomenological validity of an OCD-memory model and the remember/know distinction. Behaviour Research and Therapy, 41(3), 369–378

[13] Davey GCL (2018) The Anxiety Epidemic. Little Brown Books.