Decoupling and Habit Reversal Training — Self-Help Treatment to Reduce Nail Biting, Trichotillomania, Skin Picking (Farsi)

and Other Body-Focused Repetitive Behaviors (BFRB)

Excessive nail biting (biting one’s fingernails and/or the adjacent skin) and the compulsive pulling of one’s hair (trichotillomania) are impulse control disorders that are classified as BFRB.

Although the direct health consequences of nail biting are rarely severe apart from an occasional infection of the nail bed, the psychological consequences are often grave. Bitten nails are easily visible and often evoke disgust in other people. In the general population, nail biting is often equated with a nervous temperament and difficulty controlling impulsive behaviors. Many sufferers are ashamed to shake other people’s hands because of the appearance of their own hands. This may in turn prompt low self-esteem and social insecurity. Some patients try to hide their fingernails, which paradoxically makes the disorder even more conspicuous.

Full, thick hair is commonly associated with health, whereas bald or balding areas on the head or the lack of eyelashes and eyebrows (typical features of trichotillomania) are often mistaken for a severe somatic illness, such as cancer. People with trichotillomania are frequently ashamed of their appearance and conceal bald patches with caps, scarves, or wigs. In many cases, sufferers totally seclude themselves from their social environment, which substantially lowers their quality of life.

Pathological skin picking is another BFRB, and it is characterized by repetitive scratching, biting, and picking at the skin. Like the aforementioned behaviors, it is often associated with a low quality of life and can result in severe somatic problems.

Further information

For further information on trichotillomania, please visit the Trichotillomania Learning Center (TLC) at The Trichotillomania Learning Center is a nonprofit organization based in the United States whose mission is to improve the quality of life of children, adolescents, and adults with trichotillomania and related body-focused repetitive behaviors such as skin picking. TLC works to raise awareness of these disorders, promote research and treatment advances, and provide information and support to sufferers and their families.


We would like to thank Jennifer Raikes, Executive Director of the TLC Foundation for Body-Focused Repetitive Behaviors, for her helpful comments on an earlier draft of the manual on decoupling.

Preliminary Research Results on Decoupling

The feasibility and effectiveness of our approach for trichotillomania was established in a randomized-control study (Moritz & Rufer, 2010), which is summarized below.

Trichotillomania (TTM) is classified as an impulse control disorder characterized by the recurrent urge to pull out one’s own hair, resulting in noticeable hair loss. Cognitive behavioral therapy, involving habit-reversal training, currently represents the treatment of choice. A study by Moritz and Rufer (2010) assessed the feasibility and effectiveness of a novel technique called decoupling (DC). DC aims to attenuate TTM by having individuals perform movements that decouple the movements and behavioral elements involved in hair pulling (i.e., performing a different behavior than hair pulling when the urge arises; see manual). For the study, a total of 42 subjects with TTM were recruited via self-help forums. They completed an Internet survey, after which they were randomized either to DC or progressive muscle relaxation. After four weeks, participants were asked to fill out the same questionnaires and rate observed changes in symptoms (i.e., the effectiveness of the intervention).

The completion rate was high (91%). The DC group showed a significantly greater decline relative to progressive muscle relaxation on the Massachusetts General Hospital Hair Pulling Scale, which served as the primary outcome, indicating a medium to strong effect size. Declines on scales tapping symptoms of depression and obsessive-compulsive disorder were, however, comparable between the two groups. Despite methodological limitations and the need for replication, including a longer-term follow-up assessment and expert ratings of the intervention, the present study suggests that DC may prove beneficial to a substantial number of individuals with TTM.

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