Compulsive hair pulling is a psychological condition known as trichotillomania, or trich, and it's estimated that as many as 11 million Americans suffer from it.
Trich is an impulse-control disorder and those with it can't overcome the overwhelming urge to pull out their own hair -- be it from the scalp or crown of the head, their eyelashes, eyebrows or any other part of the body. The hair pulling is so extreme that it results in bald patches. Those afflicted often experience feelings of tension or anxiety that aren't relieved until they pull, which gives the individual a sense of relief or pleasure. In addition to pulling, those with the disorder may also chew or eat their hair.
"Impulse control disorders," Szopa explains, "are different from addictions, though both stem from feelings of low personal control. People who struggle with impulse control disorders have difficulty delaying the gratification of many types of urges in a wide variety of circumstances, and they have difficulty anticipating the negative results of satisfying those urges."