Apparent covariation between child habit disorders: effects of successful treatment for thumb sucking on untargeted chronic hair pulling.

We evaluated the effects of aversive taste treatment of thumb sucking on untreated trichotillomania (habitual hair pulling) in two children who chronically pulled their hair and sucked their thumbs. A combination of withdrawal and nonconcurrent multiple baseline designs showed that, concomitant with the successful treatment of thumb sucking, hair pulling was also eliminated. The results suggest an efficient method for changing behaviors that are difficult to treat directly.