Self-injurious behaviour and body site preference.

Self-injury by people with intellectual disabilities is a highly problematic and damaging behaviour with profound implications for quality of life. To date, very little detailed descriptive information has been available on the distribution and location of body sites that are injured. This study presents preliminary information on the locations of the self-injury body sites of 29 school-age individuals with developmental and intellectual disabilities who self-injured daily. Teaching staff in school-based special education programmes independently recorded the body locations of where their student's self-injured. Approximately 80% of the reported self-injury was directed disproportionately toward the head and hands. Three-quarters of head-directed self-injury was located on the front of the head, and 83% of hand-directed self-injury was located on the back of the hands. Furthermore, 32% of the body sites toward which self-injury was directed were located on stimulation-produced analgesia body sites. The implications of these findings are discussed in relation to the opioid hypothesis of self-injurious behaviour, and with regard to future research investigating functional diagnostic strategies considering both social and biological variables.