The Role of Fear Conditioning in OCD
By Paul R. Munford, Ph.D.
One of the earliest, and better, psychological explanations for the acquisition and elimination of OCD symptoms is Mower's two-stage theory (Mower, O. H. 1947). In the first stage, classical conditioning occurs. The best-known example of classical conditioning is Pavlov's experiment that conditioned a dog to salivate by ringing a bell. This was achieved by ringing a bell (a neutral stimulus) and presenting the animal with meat powder, a substance that naturally elicits salivation (and unconditioned stimulus). After a number of such pairings of the meat powder and bell, the dog salivated in response to the bell alone. The bell had been transformed from a neutral stimulus to a conditioned stimulus for salvation. Classical conditioning works with people as well. For example, if a person has an unexpected frightening experience, for instance being robbed at gunpoint by a short man (unconditioned stimulus), he or she can become fearful of other short men (conditioned stimuli) even though the person knows most short men are harmless. Thus, short men who were previously neutral stimuli, having been paired with the trauma of robbery, are transformed into conditioned fear stimuli. This is classical conditioning of fear.
Mary's case is a good example of the first stage of Mower’s theory on the acquisition of obsessions. She recalled that as a seven-year-old child she developed a fear of contracting cancer from an aunt with terminal carcinoma who came to live with her family. The aunt had a favorite chair she always sat in that Mary associated with her fear of cancer, so that eventually, simply the site of the chair provoked dread in the child. Thus, by means of classical conditioning, the chair became a conditioned stimulus for fear and anxiety.
However, in OCD the conditioning does not stop with just one association of a neutral and feared stimulus. It continues by means of higher order conditioning to include more and more situations, objects, and events. Continuing with Mary's example -- other people sat in the aunt's chair; and by means of higher order conditioning, they too became conditioned stimuli for fear. Furthermore, the aunt sat on other furniture and touched other objects in the house. So a kind of fear conditioning contagion took place that transformed many non-fearful situations, events, circumstances, people, etc., into conditioned stimuli for fear. By the time Mary started treatment as a 51-year-old single, woman she felt contaminated whenever she ventured from her apartment into the outside world that she now considered teaming with triggers for cancer. So to prevent cancer, immediately upon coming home, just inside the doorway, she practiced the compulsion of completely undressing, depositing her clothes in a special container, and then sponging down her entire body with alcohol to "decontaminate herself": then she felt "comfy." If she didn't wash, she experienced intense anxiety until she did. Her bathing is an example of the second stage of Mower’s two-stage theory.
In Mower's second stage, operant conditioning occurs. This type of conditioning happens when behaviors become more frequent if followed by satisfying consequences but less frequent if followed by aversive consequences. Everyday examples include awarding bonuses to employees for increased production, or docking employees for missing deadlines. In OCD, people, motivated to relieve fear, learn by trial and error to perform certain compulsive behaviors or mental activities that result in the satisfying consequences of diminished anxiety -- but only until the next cycle of obsession and compulsions. Nevertheless the immediate reward from anxiety relief is positive enough to perpetuate ongoing compulsions in response to continuing obsessions. Once the rituals are established, they become entrenched as the only means of coping with fear and thereby prevent habituation. That is, if the person sits with the fear, it naturally burns itself out as the physiological resources for "fight or flight” are depleted, and the fear is extinguished.
Fortunately, both forms of conditioning can be eliminated through the process of extinction. This requires exposure to conditioned fear triggers (e.g., things that stimulate the fear of contracting cancer) in the absence of the unconditioned stimulus (e.g. actually contracting cancer), which neutralizes the conditioned fear triggers, rendering them incapable of provoking further distress. For OCD, this means repeatedly exposing the person to the conditioned fear triggers only. The unconditioned fear is always absent because the dangers posed by obsessions are always unreal or highly unlikely (e.g., contracting cancer from exposure to the outside world).
As a result, the fear triggering content of the obsessions is extinguished. Having been unaware of the need to experience the fear instead of avoiding or blocking it, patients have distracted themselves by using avoidance and rituals and therefore have not experienced habituation, the natural elimination of anxiety, from exposure to obsessions not followed by rituals. In other words, instead of avoiding contact with fear, it must be faced. With the elimination of the conditioned fear, the obsessions fade away, and with no obsessions there is no need for further compulsions. Mower’s theoretical formulation was the basis for the first successful psychological treatment of OCD by Victor Meyer in 1966 (Meyer, 1966). His treatment techniques were further developed and promulgated by Edna Foa and others, hence redefining OCD as highly treatable by the technique now known as exposure and ritual prevention (ERP)
Returning to our case example, Mary was treated with exposure and ritual prevention exercises by systematically practicing exposure to the conditioned fear triggers outside her apartment and then refraining from washing rituals until the anxiety triggered by the exposures had dissipated. After repeated practice her obsessions lost their power to provoke fear, and she washed normally. Many people wonder why this elimination of fear has not yet occurred in view of the fact that they have been exposed to it for months or even years. The answer is that they escape from it by ritualizing and avoiding, thereby preventing sufficient exposure. But once the obsessions receive extended and repeated exposure to the light of day -- as is the case with vampires as well -- they fade away and can even disappear.
Scientific studies show that these techniques significantly reduce symptoms in 75 percent of those treated (Foa & Kozak, 1996). Furthermore, a study my UCLA colleagues and I conducted demonstrated that exposure and response prevention is associated with changes in the brain chemistry of OCD patients that are correlated with reductions in their symptoms (Baxter et al. 1992).
Paul R. Munford, Ph.D. is a clinical psychologist and director of the Cognitive Behavior Therapy Center for OCD and Anxiety in San Rafael California.
Baxter, L. J., J. M. Schwartz, K. S. Bergman, M. P.Szuba, B. Guze,
J. C.Mazziotta, A.Alazraki, C. E. Selin, H. K. Ferng, P. Munford, and M. E. Phelps. 1992. Caudate glucose metabolic rate changes with both drug and behavior therapy for obsessive-compulsive disorder. Archives of General Psychiatry 49(9): 681-689.
Foa, E. B., and M. J. Kozak. 1996. Psychological treatment for obsessive-compulsive disorder. In Long-term Treatments of the Anxiety Disorders, Edited by M. R.Mavissakalian and R. F.Prien. Washington, DC: American Psychiatric Press.
Meyer, V. 1966. Modification of expectations in cases with obsessional rituals. Behavior Research and Therapy 4:273-280.
Mower, H. O. (1947). On the dual nature of learning -- A re-interpretation of "conditioning" and "problem-solving." Harvard Educational Review, 17, 102-148.
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