What underlying processes may cause behavior change in treatment?
A frontline treatment for OCD—and many anxiety disorders—is Exposure and Response Prevention (ERP). ERP involves exposure to the feared stimuli (the exposure part of treatment) and simultaneous prevention of the ritual that is typically performed in the face of the anxiety-provoking stimuli or obsession (the response prevention part of treatment).
Several randomized controlled trials have found ERP to be as efficacious as medication and to have longer benefits than medication alone, since the effects of successful ERP treatment last beyond the treatment itself, while OCD symptoms return once the medication is stopped.
Habituation vs. Inhibitory Learning Models
There are two cognitive models that attempt to explain the mechanism by which ERP for OCD works: the habituation model and the inhibitory learning model.
In OCD, habituation refers to the diminishing of an anxious physiological and fearful emotional response to frequently repeated stimuli. In ERP, habituation is hypothesized to work by shifting the belief systems a patient has (e.g., overestimation of the risk of accidentally harming someone nearby) and reducing the link between the belief and the threat appraisal.
Emotion Processing Theory, part of a Cognitive Behavioral Therapy model, asserts that patients learn new implicit and powerful lessons when they engage in ERP treatment. One such lesson has to do with the “fight or flight” system. Patients learn during ERP that their sympathetic nervous system, responsible for the physiological part of anxiety, is unable to maintain a fight or flight response indefinitely. The habituation model of ERP suggests that after some time doing an exposure, usually at least one hour, the parasympathetic nervous system is triggered to settle down the sympathetic nervous system, regardless of the person’s cognitive interpretation of what is happening. In response to this process of achieving homeostasis in the face of a feared stimulus, the individual incorporates corrective information into his or her cognitive schemas.
In essence, habituation changes behaviors first; in turn, cognitions are modified due to the behavioral proof; and emotions change last in response to the altered cognition.
An example of this process would be a patient who is engaging in an ERP to challenge his obsessions of contamination by contracting a deadly illness. In the presence of a therapist, the patient touches sinks, communal door handles, toilet seats, and bathroom floors (exposure) and goes to eat lunch without being allowed to wash his hands (response prevention).
The patient initially experiences heightened spikes of anxiety during this process but continues to engage in the exposure despite it. While doing the bathroom exposure, the person’s physiological signs of anxiety begin to subside despite the fact that he still cognitively associates the bathroom with “dirty” and with “disease.” After doing this exposure and eating lunch, the patient realizes he or she did not become deathly ill despite not being able to wash his hands after touching dirty items, so he modifies the association between bathroom and illness in his head to lessen the likelihood of threat in his cognitive schema related to bathrooms.
Author: Sarah-Nicole Bostan, M.A.