Long-term effects of naltrexone on self-injurious behavior

A subgroup of self-injuring patients responds positively to the opiate-blocking agent naltrexone in acute, double-blind studies. In this study we examined the effects of naltrexone after acute treatment and the long-term effects of naltrexone on SIB. Rates of SIB were collected from pretreatment baseline; a second baseline a year after the acute trial; and a subsequent 12-month double-blind, placebo-controlled treatment. A subgroup of patients decreased SIB for a year without treatment after acute exposure to naltrexone. Five participants who decreased SIB by 70% after acute treatment increased SIB to the long-term treatment with naltrexone. In contrast, those for whom SIB increased over the one-year treatment hiatus decreased their SIB after the first long-term treatment. Discussion of these complex effects considered the role of background opioid levels, dosing, and treatment regimen of naltrexone and other factors limiting receptor adaptation among patients who exhibit SIB.