Treatment and extended follow-up of chronic hand mouthing.

This study evaluated the relative effectiveness of differential reinforcement of other behaviors (DRO), differential reinforcement of incompatible behavior (DRI), and contingent watermist (CWM) in treating chronic self-injurious hand mouthing. The participant, a man with profound mental retardation, lived in a large residential facility. Prior to treatment he had participated in ineffective nonaversive treatments and was continuously mechanically restrained by his attending physician to promote healing of his hands. Baseline data collected in daily 30-minute sessions showed a hand mouthing rate of 1.5 responses/minute. Implementing the DRO, DRI, and CWM procedures in combination resulted in an initial 85% rate reduction. Each treatment component subsequently was withdrawn and reintroduced systematically in order to evaluate its relative effective upon hand mouthing. Only CWM plus differential reinforcement (DRO and/or DRI) had a significant effect upon hand mouthing. DRO plus DRI procedures were ineffective. In an effort to promote generalization of treatment effects, subsequent manipulations evaluated the effects of therapist proximity to the participant (one foot, 21 feet, or a random distance between one and 21 feet). Hand mouthing rates were reliably lower in the one-foot condition than in the 21-feet condition. The random proximity condition produced an intermediate performance. Direct care staff have implemented the DRI and CWM procedures throughout the participant's waking hours for nearly 3 years with almost complete elimination of hand mouthing.