An unusual disorder leaves its sufferers with bare eyebrows, bare eyelashes, a ragged scalp that even a wig might not cover, and a very damaged self-esteem.
Trichotillomania, a psychiatric disorder that drives people to compulsively pull their hair, leaves behind scars worse than bald patches.
"Those who suffer with 'trich' suffer twice," said Dr. Tamar Chansky, director of the Children's Center for Obsessive Compulsive Disorder and Anxiety in Philadelphia.
"Not only because they have this condition that interferes with their freedom -- how to wear their hair, whether they can swim or ride a bike. It also wreaks havoc on their self-esteem."
Between 3 percent and 5 percent of the population suffer this compulsive hair-pulling, but they often hide their habit.
As a result, the disorder often goes undiagnosed and untreated, researchers said.
Trich patients feel like they have a terrible secret that they need to keep private, for fear that no one will understand why they "do this" to themselves, Chansky said.
Experts aren't certain what causes trich.
It usually starts during early adolescence, but scientists at Duke University have recently found that the disorder might sometimes be due to a genetic mutation.
This finding is preliminary, but very exciting, experts say.
To the patients who suffer from this painful disorder, this discovery says, "It's not your fault," experts say.
"This is an important first in understanding the genetics of not only trichotillomania but any disorder where people have unwanted behaviors that they can't control," said Dr. Allison Ashley-Koch, the study's author and a researcher at the Duke University Center for Human Genetics.
"This opens the door and tells us that genes can be associated with this and other impulse-control disorders."
The scientists studied 44 families where one or more family members suffered from trich.
They looked specifically at a gene known as SLITRK1.
Scientists already know that SLITRK1 is linked to another impulse-control disorder that doctors think is related to trich, Tourette's syndrome.
In two of the 44 families, both the trich patient and one parent had a mutated copy of the SLITRK1 gene.
Family members who did not show any signs of trich did not have that genetic mutation.
Researchers think that the SLITRK1 mutation is somehow related to the disorder itself, and suggested that gene variations were responsible for about 5 percent of trich cases.
Scientists already know that the SLITRK1 gene helps form connections between brain cells so that brain cells can communicate with one another.
They think that the mutations in SLITRK1 cause neurons to develop faulty connections, and that this faulty "wiring" produces the urge to pull one's hair.
The discovery could definitely help doctors who are searching to treat the disorder.
If doctors know that a faulty gene could be responsible, they might be able to find a treatment by trying to fix that gene. Psychiatric medications such as Prozac have worked for some patients.
Doctors currently use a lot of cognitive-behavioral therapy for trich. Alternative therapies such as hypnosis or biofeedback might also be helpful.
But the SLITRK1 discovery could also be a tremendous help to patients by helping patients realize that this problem is not their own fault.