The cause of trichotillomania is not known. Because hair has prominent symbolic importance in most cultures and has been equated with beauty in women and power in men, it is not surprising that various psychological interpretations of hair pulling have been proposed. Some emphasize principles of learning and conditioning as critical mechanisms in the genesis and development of trichotillomania. Other explanations suggest that biological factors play significant roles. So far, the validity of these explanations has not been established using systematic scientific methods. It is likely that more than one mechanism is responsible for the disorder.
Trichotillomania is currently categorized as an impulse control disorder in which the urge to pull hair is associated with an increasing sense of tension. The act of pulling itself is presumed to relieve that tension. Trichotillomania has been considered a habit, like nail biting, that can have both a soothing function and potentially distressing consequences. The possibility that trichotillomania is associated with neurological conditions marked by motor tics, such as Tourette’s disorder, has been suggested since hair pulling, like tics, can be viewed as an uncontrollable response to an irresistible situation. Trichotillomania also has been viewed as a form of obsessive-compulsive disorder (OCD) because of the repetitive and seemingly compulsive nature of hair pulling, though significant differences between trichotillomania and OCD have been noted.
Many individuals who pull out their hair also suffer from other disorders, the most common being anxiety and depression. Professional care of individuals with trichotillomania should therefore include a diagnostic assessment that addresses the broader impact of the disorder on the individual.