Neurotic Disorders. Biological Theory of Obsessions and Pharmacotherapy
Published on Sunday, July 3rd, 2011 at 11:46 pm and is filed under Mental Health
Partly due to the fact that obsessive-compulsive disorder in the past so badly defied explanation, researchers and psychiatrists are constantly trying to find the hidden biological factors that may be associated with it. In recent years, their efforts were rewarded with the development of promising biological therapies.
Biological theory ofthe formation ofan obsessive-compulsive disorder
Two lines of a scientific explanation of biological causes of obsessive-compulsive disorder look promising. One of them points to an abnormally low activity of neurotransmitter serotonin, another – on the abnormal functioning of certain key areas of the brain in people suffering from this disorder.
Serotonin, like GABA, and norepinephrine, is a chemical compound that carries information from neuron to neuron. His relationship with obsessive - compulsive disorder has been established thanks to the discovery of antidepressants. Clinical researchers have discovered that two drugs from the group of antidepressants, clomipramine (Anafranil) and fluoxetine (Prozac), reduce obsessive and compulsive symptoms. Based on the fact that these drugs also increase the activity of serotonin, some researchers have concluded that obsessive - compulsive disorder is a result of low serotonin activity. Indeed, only those antidepressants that increase serotonin’s activity help in cases of obsessive - compulsive disorder, antidepressants, which affect mostly on other mediators do not give a similar effect.
Serotonin – a neurotransmitter, the abnormal activity of which is associated with depression, obsessive – compulsive disorder and eating disorders.
Another line of research that relates obsessive – compulsive disorder with abnormal functioning of the two areas of the brain is: the lower surface of the cortex of the frontal lobes (orbital frontal cortex), located above the eyes, and caudate nucleus, structures that are part of the basal ganglia of the brain. Together, they are involved in brain cycle, which converts sensory information into thought and action. The cycle begins in the cortex of the lower surface of the frontal lobes, where usually there are sexual, aggressive and other primitive impulses. Then these pulses are moved to the caudate nucleus, into a loop as a filter and then sent the most powerful impulses to the thalamus, the following system in the loop. If the impulses reach the thalamus, a person is forced to think about them further, and perhaps to act. Many advocates of biological theory now believe that the lower surface of the cortex or frontal lobes, caudate nucleus, or some people are too active, leading to a continuous break of painful thoughts and actions.
Cora of the lower surface of the frontal lobes is the brain area, which usually occur impulses that cause sexual, aggressive and other primitive activity.
Caudate nucleus – structures in the basal ganglia of the brain that help to translate sensory information into thought and action.
In support of this theory is long-term medical monitoring of the attenuation of symptoms or obsessive – compulsive disorder due to damage to the lower surface of the cortex of the frontal lobes, caudate nuclei and adjacent areas of the brain as a result of accident or illness. Positron – emission tomography (PET – scanning), which gives the picture of brain activity showed that the caudate nucleus and the cortex of the lower surface of the frontal lobes of patients with obsessive – compulsive disorder are more active than the control group.
These lines of research can be linked. Since the neurotransmitter serotonin plays an important role in the processes taking place in the cortex of the lower surface of the frontal lobes and caudate nuclei, the low activity may seriously disturb the normal functioning of these areas.
Psychological notes. By the time of man’s birth the individual neurons in his brain formed more than 50 billion synapses, or connections. During the first months of life, their number increased twenty-fold, reaching more than 1000 billion.
Biologicaltreatmentsof obsessive-compulsive disorder
As it was mentioned above, the researchers found that certain antidepressants are useful for the treatment of obsessive - compulsive disorder. They not only enhance the activity of serotonin in the brain, but also provide a closer to normal activity in the cortex of the lower surface of the frontal lobes and caudate nuclei.
Studies have shown that the use of clomipramine (Anafranil), fluoxetine (Prozac) and fluvoxamine causes an improvement in 50-80% of people suffering from obsessive -compulsive disorder. Obsessions and compulsions of people who take these antidepressants usually do not disappear completely, but reduce on average twice during a height weeks of treatment.
Thus, people, improvement of which is based only on medical therapy, tend to suffer relapses after drug withdrawal.
In this way, methods of treatment of obsessive – compulsive disorder, as well as treatment of panic disorder, have undergone significant improvements over the last decade. The former once serious problem, obsessive – compulsive disorder is now amenable to several forms of therapy, especially there are commonly used method of immersion (exposure) and to prevent retaliation and treatment with antidepressants (these procedures are often combined). Moreover, at least two important studies suggest that the behaviorist and biological approaches may eventually provide the same effect on the brain.
In these studies, in people treated with the method of exposure and response prevention, and in people taking antidepressants was found a marked decrease in activity in the caudate nuclei. This is the first such direct communication of relation between psychotherapy mental disorder and changes in the functioning of the brain.