Videan, E. N., Ely, J., Lammey, M. et al. 2008. Successful elimination of self-injurious behavior (SIB) in a chimpanzee (Pan troglodytes): a case study using a combination of risperidone and environmental enrichment. American Journal of Primatology 70(S1), 50. (31st Meeting of the American Society of Primatologists Scientific Program, Abstract #91)

Self-injurious behavior (SIB) can result in open wounds, tissue damage, and increased risk of infection. In many cases, increased environmental enrichment is not consistently effective in eliminating this behavior. We report here on the successful elimination of SIB in a 22 year old, socially-housed male chimpanzee (Pan troglodytes) with a history of single housing during infancy (age 1–6yrs). The frequency of SIB was collected from veterinary records. Additional behavioral data were collected during initial baseline (7.8hrs), increased enrichment (7.2hrs), and combined enrichment and drug (Risperidone) intervention (10.4hrs) periods. Prior to intervention, mild to moderate SIB occurred at a rate of 0.70 episodes per month. Other stereotypies occurred during 17% of behavioral observations. During a six month period of increased environmental and occupational enrichment (i.e., increased use of puzzle feeders, primadome access), mild to moderate SIB occurred at a rate of 0.60 episodes per month and stereotypies decreased to 11% of observations. A daily 3mg Risperidone dose, an atypical antipsychotic, was then added to the enrichment treatment plan. Risperidone is well tolerated in macaques, however no information regarding its effectiveness in reducing SIB exists. In 10 weeks, there have been no episodes of SIB and other stereotypies have decreased to 0.7% of observations. Further, there have been no observed behavioral or physiological side effects. The combination of enrichment with Risperidone treatment was effective in eliminating SIB in this chimpanzee.