Treating nailbiting: a comparative analysis of mild aversion and competing response therapies.

This study compared two methods of treating nail-biting. One method involved the use of a mild aversive stimulus in which subjects painted a bitter substance on their nails, and the other required the subject to perform a competing response whenever they had the urge to bite or found themselves biting their nails. Both methods included self-monitoring of the behaviour, and a third group of subjects performed self-monitoring alone as a control condition. The study lasted four weeks. Twenty-one subjects, seven per group, participated. Both methods resulted in significant improvements in nail length, with the competing response method showing the most beneficial effect. There was no significant improvement for the control group. The competing response condition also yielded significant improvements along other dimensions such as degree of skin damage and subjects own ratings of their control over their habit. These were not seen for the other two conditions. The benefits of this abridged version of Azrin and Nunn's (Behaviour Research and Therapy, 11, 619-628, 1973) habit reversal method in terms of treatment success, use of therapist time and client satisfaction, are discussed.