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The Low-Down on OCD
For many years, Obsessive Compulsive Disorder (OCD) was thought of as a relatively rare disorder, caused by unconscious conflict, and very difficult to treat. OCD is now viewed as one of the most common psychiatric disorders (the fourth most common in one important study) and one of the most disabling of all medical disorders. Around 2-3% of all people, male and female will get OCD.
People with obsessive-compulsive disorder (OCD) suffer from obsessions and compulsions. Obsessions are repetitive thoughts or images that the person finds intrusive and inappropriate, and that increases levels of anxiety. Compulsions are repetitive rituals (thoughts or actions) designed to counter obsessions and lower anxiety. For example, a person with obsessions about contamination may wash their hands repetitively, or a person with obsessions about possible harm may check repeatedly.
While washing and checking are easily recognized, many people have more abstract symptoms, such as having to pray over and over to get rid of blasphemous thoughts, or suffering from intrusive sexual thoughts, or having to hoard excessively. In addition to obsessions and compulsions, people with OCD may show avoidance behaviours; for example, the person with contamination concerns may simply stay indoors rather than risk going outdoors, feeling contaminated, and then having to spend hours cleaning and washing. Other people with OCD may take an extraordinary long time to complete routine daily activities; this is a form of OCD known as obsessional slowness.
Around 2-3% of people will develop OCD during the course of their lifetime. It is equally common in males and females, and appears to occur at similar rates throughout the world. OCD often begins in childhood, perhaps particularly in males. In females, another common age of onset is at the time of pregnancy or giving birth; hormonal interactions with brain chemicals are likely to play an important role in such cases.
One subtype of OCD begins after certain infections, typically after a Streptococcal throat infection. This condition is termed PANDAS or Paediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcus. In such cases the body's reaction to the Streptococcus bacterium mistakenly attacks a part of the brain called the basal ganglia (discussed in more detail below), resulting in acute onset of OCD symptoms and/or tics.
Various neurochemical systems are thought to be important in mediating OCD symptoms; these include the serotonin and dopamine systems. Genetic influences have been hypothesized, and indeed OCD is somewhat more common in relatives of people with OCD than in the general population. This is a rapidly advancing area of research, and several candidate genes for OCD have already been proposed
The MRC Unit has been involved in studies of the neurochemistry and genetics of OCD. Work has been done addressing the role of the serotonin system in OCD, and in particular on the serotonin-1D receptor, which may be particularly important. They are currently focusing on a range of serotonergic and dopaminergic genes in OCD
OCD responds to a class of medications known as serotonin reuptake inhibitors (SRIs), and not to other kinds of antidepressants. Brain imaging studies show that hyperactive basal ganglia in OCD are normalized after long-term treatment with SRIs. The MRC Unit is involved in several treatment trials of OCD, and has a particular interest in developing new treatments for people who have failed to respond to the SRIs. In this work, an "augmentation strategy" approach is often used, in which a second agent is added to the original SRI.
Another treatment route is turning down the putative false grooming/danger alarm in OCD by tricking the brain through exposure techniques. The evidence seems clear that by increasing exposure to feared stimuli there is ultimately a decrease in symptoms as well as normalization of basal ganglia function. It turns out that precisely the same brain changes occur after behavioural therapy as occur after medication treatment; both interventions lead to a decrease in the basal ganglia false alarm.
Obsessive-compulsive disorder can be a chronic debilitating illness. OCD is the 10th most important cause of disability worldwide. MRC Unit Together with the Mental Health Information Centre and consumer groups like the Obsessive-Compulsive Disorders Association of South Africa have worked to increased awareness of the condition and to encourage people to seek appropriate treatment.
The Research Unit on Anxiety and Stress Disorders was initiated by the Medical Research Council (MRC) of South Africa in 1997. The Unit, which is located in the Dept of Psychiatry of the University of Stellenbosch in the northern suburbs of Cape Town, researches the psychobiology and treatment of the anxiety disorders. The Unit is currently contributing to a range of promising areas, including the genetics of the anxiety disorders, brain imaging, and pharmacotherapy of treatment-resistant patients. Perhaps most importantly, the Unit is now able to treat people suffering from anxiety disorders with considerable success.
This article prepared with assistance from Christine Lochner, MRC Unit on
Anxiety and Stress Disorders.
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