Humans with the trichotillomania disorder have been known to pull their hair until it creates bald spots, while others pluck off their eyebrows and eyelashes or yank their hair until abrasions erupt. Now, researchers studying mutant genes in mice have found a link that someday could help people suffering from compulsive disorders such as trichotillomania, an obsessive disorder that leads to compulsive hair pulling.
A team from the University of Utah School of Medicine discovered that mice with mutations in the Hoxb8 gene groomed themselves twice as much as other mice, causing hair loss and open skin lesions. The gene can be found in microglia, which is a type of immune cell that originates in bone marrow and migrates to the brain. To test their theory, the researchers performed bone marrow transplants on the over-grooming mice. Once the new microglia reached their brains, they displayed normal, noncompulsive grooming behavior.
The researchers’ line of reasoning follows other research into microglia and immune system breakdowns that lead to the onset of an obsessive compulsive disorder (OCD). For example, there’s a condition called Sydenham’s chorea, which results in rapid, involuntary jerking movements and psychological symptoms such as obsessions and compulsion. Researchers have found that Sydenham’s chorea can be brought on by acute rheumatic fever, a type of autoimmune disorder.
One major hurdle for researchers studying OCD behavior in animals has been the nature of the neuropsychiatric symptoms in humans. The ritualized behavior of a compulsion has been linked to the anxiety and tension brought on by obsessions, which are intrusive thoughts that people can’t shake. Since mice can’t verbally report their feelings, researchers are limited when comparing animal behavior to physical compulsive behavior such as trichotillomania. The findings, however, could prove to be a valuable tool for neurobiological studies of OCD and shed more light on the roles of different microglia in the brain.
Trichotillomania goes far beyond those times when you feel like pulling your hair out due to some passing frustration. Children and adults who suffer from the condition often find it hard to talk about. If you think you’re suffering from this type of OCD, seek out medical help. There also are support groups and success stories out there. If you’re looking for more information, a good clearinghouse is the Trichotillomania Learning Center.