Biology 202
2000 First Web Report
On Serendip

Obsessive-compulsive disorder is composed of two major constituents evident in its very name - obsessions and compulsions.  Obsessions are recurring thoughts or impulses that seem to invade one's mind despite attempts to ignore or suppress them (4).  Though these thoughts range from the tedious and seemingly innocuous sort, to the shameful and morbid kind, all are generally viewed as senseless and are accompanied by anxiety to some degree (4).  Some common examples of obsessions include:  fear of germs or contaminants, fear of aggressive sexual impulses towards one's self or others, thoughts of harming one's self or others, and doubting reality (for example, a person doubting whether or not she turned off the stove before she left the house, even though she made sure she did several times) (4).

The second major component of OCD are compulsions, or voluntary, irresistible actions that are apparently stereotyped or ritualistic (4). Approximately 80% of all OCD sufferers experience compulsions along with obsessions (4), while only 20% experience one of the two. A person with OCD may be driven to perform the compulsive act in order to produce or prevent another situation from happening. In most cases, the compulsive person is aware that the act is meaningless or unreasonable, however, avoiding the urge to perform the act often leads to unsurpassable amounts of stress and anxiety (4). Only when the act is carried out is the person's anxiety once again relieved. Examples of compulsions include:  hand washing or wearing gloves, ordering and arranging items in specific ways, and checking rituals involving locks and appliances (2).

Strong evidence suggests that OCD has both psychological and biological components (3). In the past, the causes of OCD have strictly been attributed to external factors such as family problems or learned behaviors (such as an emphasis on cleanliness). However, when OCD-like behavior was observed in other animal species including dogs, horses, and birds, attention was redirected to finding a neurobiological cause for the disorder as well as environmental influences (3). OCD appears to arise from defects in the neurochemical functioning of the brain, specifically due to an increase of activity in the orbital frontal cortex and caudate nucleus (3). The orbital frontal cortex is responsible for a human's perception of fear and danger, whereas the caudate nucleus is instrumental in a person's ability to start or stop different actions and ideas (3). Increased levels of activity in these regions have been linked to some of the key symptoms of OCD. In addition, brain imaging studies have compared OCD sufferers with non-OCD sufferers by using a method known as positron emission tomography (PET) (1). The results showed that patients with OCD displayed different brain patterns from those without OCD, and that in patients with OCD, medication and behavioral therapy both caused changes in the caudate nucleus (1). This provided evidence that both medication and psychotherapy influence the brain.

OCD has also been linked to an imbalance in serotonin, a neurotransmitter that acts as a bridge in sending nerve impulses from one neuron to another (2). Serotonin also acts to regulate repetitive behaviors (2), and so when it functions abnormally in an OCD sufferer, it increases the likelihood that the person will experience a wide range of obsessions and compulsions.

While stress does not cause OCD (3), a correlation between stressful situations and the onset of the disorder can be seen in many cases. The highest rates of the disorder actually occur in high-stress groups, such as the young or the unemployed (4). Typically, a stressful event such as a divorce or the death of a loved one can worsen OCD symptoms already present in an individual, or trigger a relapse in a person who has since received treatment (3).

Though no cure for OCD presently exists, the disorder is highly controllable when treated with both drug therapy and behavioral therapy (3).   Presently, the most effective medications for obsessive-compulsive disorder are the selective seratonin reuptake inhibitors (SSRI's), which include Paxil, Luvox, and Zoloft (3). The antidepressant drugs, Anafranil and Prozac, which have been shown to reduce the symptoms of OCD in about 60% of the cases studied, have become the most widely used medications for the treatment of the disorder (4). All of these drugs function by affecting the brain's metabolism of serotonin, increasing its availability at the synapses in the brain (3). The success of these drugs in alleviating the symptoms of OCD give witness to the fact that serotonin levels play a major role in the development of OCD. If one drug is not effective in an individual, others should be tried as well.

Behavioral therapy is often used in conjunction with drug therapy to treat and alleviate some of the symptoms of OCD. In cases of OCD, the type of therapy used is often referred to as the "exposure and response prevention" technique (1). In this technique, a patient is deliberately and voluntarily exposed to the cause of his obsession, and is then taught ways to avoid performing the compulsions and deal with his anxiety (1). Often exposure and response prevention can be a very difficult task for the patient, for in essence, he is being forced to confront his greatest fears face-to-face, without the luxury of a quick escape.  However, the longer a patient undergoes this type of behavioral therapy, the less likely he will be to experience those same compulsions, and so his condition will greatly improve. It has been shown that 80% of those that undergo both drug and behavioral therapies have exhibited significant improvement (3).

The vast majority of OCD sufferers can be treated without ever being admitted into the hospital (3). The medications available paired with behavioral therapy allow for marked improvement for sufferers being treated as outpatients (3). Nevertheless, in severe cases where a person with OCD simply cannot function in an every day setting, hospitalization remains an option. Regardless of whether an OCD patient is treated in or out of a hospital, treatment is vital in improving his condition, for if left untreated, the disorder will continue indefinitely (3). With the wide range of treatment options available to OCD sufferers and the extensive studies being conducted in lieu of the disorder, the promise of a future with less worries and anxiety appears to be well within reach.

WWW Sources

2) Obsessive-Compulsive Disorder:  What Is It and How To Treat It

3) Most Frequently Asked Questions About OCD

4) Obsessive-Compulsive Disorder , on the Encyclopaedia Britannica website

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