Two main varieties of desensitization therapy are commonly used. In systematic desensitization, patients who suffer from anxiety, phobias, or related conditions are gradually exposed to the stimuli that elicit a fear response, with the goal of reducing that fear response over time. A newer, and still somewhat controversial, variety of desensitization therapy relies on rapid eye movements to gradually reprogram the brain’s responses to certain stimuli.
Systematic desensitization therapy was originally developed as a treatment for patients who suffered from irrational fears. Unfounded fear of the dark, snakes, spiders, crowds, heights, enclosed spaces, and many other relatively ordinary stimuli is relatively common. These fears can greatly limit a patient’s ability to interact appropriately with the world.
A patient will often encounter a stimulus, experience fear, allow that fear to dictate his or her actions, flee from the stimulus, and then feel relief. This cyclical process tends to strengthen both the phobia and the sense of relief felt upon escape from the stimulus. In untreated patients, this process can cause phobias and anxieties to become more deeply-ingrained over time.
Desensitization therapy seeks to break this cycle. Patients are instructed in techniques for managing small amounts of fear and anxiety. They are then exposed to very minor stimuli, such as a spider at a distance in a plastic box, or slightly lowered room lighting. These stimuli evoke a mild fear response Patients resist the urge to flee, confront their fear, and gradually become comfortable with the mild stimuli.
Once patients have dealt with one level of fear stimulus successfully, the process is repeated with more powerful stimuli. The spider box might be moved closer to a patient, or the lighting dropped more dramatically. A patient would again be moderately fearful, but if the therapy is carefully managed, not so fearful that he or she panics. Fear management techniques can then be used on the new, more dramatic fear stimuli. This therapy is designed to make patients comfortable with even major stimuli over time.
Eye movement desensitization and reprocessing therapy is a different sort of desensitization therapy. This specialized therapy attempts to reprogram a portion of the brain, in order to allow a patient to process and gain mastery over traumatic memories. It is used largely to treat post-traumatic stress disorder (PTSD).
EMDR therapy uses visual stimuli, such as a rapidly moving object, to distract the brain during the course of the discussion of a painful memory. The precise functioning of this therapy is not understood, but it is believed to disrupt a brain’s unhealthy fixation on a particular moment or experience. Over time, a patient undergoing this variety of therapy is taught to replace painful and negative memories and thoughts with positive images and thoughts.
An additional type of desensitization therapy is biological in nature, rather than psychological. This therapy treats allergies by gradually exposing the patient to larger and larger doses of allergens. In time, this process reduces the body’s histamine response to allergens, in much the same way that systematic desensitization reduces the brain’s response to fear stimuli.