Functional analysis and treatment of chronic hair pulling in a child with cri du chat syndrome: effects on co-occurring thumb sucking.

The relation between hair pulling and thumb sucking in a child with Cri du Chat syndrome was evaluated during the assessment and treatment of hair pulling. A functional analysis suggested that both behaviors were maintained by automatic reinforcement and possibly by attention. Treatment combining differential reinforcement (praise), response interruption, and access to toys decreased hair pulling. A corresponding decrease in thumb sucking was observed even though it was not directly treated. After an initial evaluation in a controlled setting, the treatment was extended to the participant's classroom setting. A 1-year follow up revealed that hair pulling, but not thumb sucking, remained at near-zero frequency. Clinical and research-to-practice implications are discussed.