It is likely that hair pulling symptoms can be linked to subtle changes in the function of the human brain. For example, other different conditions such as attention deficit hyperactivity disorder have been linked to changes in the prefrontal lobes - these are very important for regulating abilities such as attention and memory. But in contrast to many other areas of medicine, very few studies have looked at this issue in trichotillomania.
We compared people with trichotillomania and volunteers without trichotillomania on some computer tests of memory, attention, and the ability to stop repetitive behaviour. The idea is that these tests are sensitive to what is going on in particular parts of the brain. We also included people with obsessive compulsive disorder (OCD), as some researchers consider trichotillomania to be an OCD-subtype (though in my view the evidence is against this).
We found that people with OCD had problems across many cognitive abilities - memory, attention, and planning things ahead. In contrast, people with trichotillomania were very good on these tests, but showed a very specific problem on the test where it was necessary to stop repetitive behaviour. We found that the degree of impairment on this 'objective' test correlated with self-rated symptom severity of hair pulling symptoms.
These findings suggest that trichotillomania is very different from OCD, and that we may be able to link it to problems in particular parts of the human brain such as the right inferior frontal gyrus (part of the frontal lobes).
We are now conducting some follow-up studies to confirm which brain regions are involved. These findings also suggest new treatment directions that need to be explored in carefully conducted studies, without raising people's hopes unduly. My hope is that research like this will make trichotillomania more widely known - in the general public and in the medical field. Many people suffer, but few people know of the condition. In my opinion trichotillomania is a type of habit condition most likely with strong genetic contributions with a physical basis in the human brain. So people shouldn't blame themselves for suffering it!
Sam Chamberlain, Research Fellow to Dr Fineberg
May 2006