Abstract: | A 15‐year‐old female diagnosed with mental retardation was admitted to an inpatient facility for the assessment and treatment of a severe behavior disorder. A behavioral treatment to reduce destructive behavior consisting of enriched environment, differential reinforcement, and time‐out was evaluated in a reversal design. Data on affect were collected during baseline and treatment phases. In addition to achieving clinically significant reductions in problem behavior, collateral improvements in positive affect were observed during treatment phases. Copyright © 2003 John Wiley & Sons, Ltd. |