Interestingly, a condition resembling obsessive-compulsive disorder (OCD) has been recognized for more than 300 years, and throughout the evolution of psychology, each school theorized about the causes of OCD.
In the early 18th century, theorists believed OCD symptoms were a religious malady comprised of intrusive thoughts perhaps delivered by demons. The psychoanalytic school dominated the greater part of the 20th century and they had their own belief on the etymology of OCD. Psychoanalytic theory suggested that obsessions and compulsions reflect maladaptive responses to unresolved conflict from early stages of psychological development. The symptoms of OCD reflect the patient’s unconscious struggle for control over drives that are unacceptable at a conscious level.
Although the psychoanalytic tradition lost favor in the last quarter of the 20th century, it left behind an emphasis on the form of OCD symptoms: recurrent, distressing, senseless, and forced thoughts and actions. Thus, the focus became more on the symptoms and perhaps what is feared by the individual with OCD, rather than why that particular individual developed OCD.
In contrast to psychoanalysis, learning theory models of OCD gained influence as a result of the success of behavior therapy. Behavior therapy upheld the theory that obsessions and compulsions are the results of abnormal learned responses and actions. Obsessions are formed when a neutral object (e.g., a rug) is associated with a stimulus that produces fear (e.g., seeing a classmate have an epileptic fit). Thus, a desk becomes connected with a fear of illness even though one did not cause the other.
Further, behaviorists maintained that compulsions are formed as the individual attempts to reduce the anxiety produced by the learned fear stimulus (in this case, a rug). Avoidance of the object and performance of compulsions reinforces the fear and perpetuates the viscous cycle of OCD. The learned fears also begin to generalize to different stimuli, and therefore a fear response to rugs can spread to other household items. Ultimately, learning theory was able to explain why some compulsions persist even when they produce, rather than reduce, anxiety.
The next frontier in explaining OCD was found in neuroscience and the development of selective serotonin reuptake inhibitors (SSRI’s), which were found to be preferentially effective in treating OCD. This led researchers to conclude that the neurochemical serotonin must play a significant role in OCD. Further, researchers have recently begun using PET scans to study OCD. This research has revealed that patients with OCD have elevated brain activity in areas of the frontal lobes (especially orbital cortex) and the basal ganglia. Until recently the basal ganglia region has been largely ignored in psychiatric illness because it was considered a primitive brain structure. However, it is not believed that the basal ganglia functions to integrate information converging from all over the brain.
Dr. Judith Rapaport has proposed a sophisticated neurological model of OCD that takes into account both anatomical and clinical features. She maintains that the basal ganglia and its connections are turned on inappropriately in OCD. The result is the emergence of self-protective behaviors such as checking and grooming. These primitive behaviors, which are stored as preprogrammed routines in the basal ganglia, unfold uncontrollably outside the reach of brain areas that command reason.