Retrospective accounts of initial subjective effects of opioids in patients treated for pain who do or do not develop opioid addiction: a pilot case-control study.

This pilot case-control study retrospectively assessed between-groups differences in subjective opioid effects in patients treated for the first time with opioids for chronic pain. Cases were individuals in an inpatient substance abuse treatment center for primary prescription opioid addiction whose initial exposure to prescription opioids was reported for chronic pain. Controls had not developed prescription opioid addiction as measured in part by close monitoring on long-term opioid therapy at a pain management center. Twenty subjects in each group completed a battery of measures to capture data related to the individual's first exposure to prescription opioids. The Morphine Benzedrine Group subscale of an adapted 49-item Addiction Center Research Inventory (ARCI), designed to measure euphoria and other drug effects, showed an average score of 8.70 (+/-4.18) in cases versus 2.55 (+/-3.36) in controls (p<0.001), indicating a significantly greater "euphoric" effect of opioids in the cases compared to the controls. Differences in the subjective response to opioids suggest that: (1) a subgroup of patients does develop euphoria when taking opioids for pain, which may be a risk factor for eventual development of prescription opioid addiction; and (2) subjective effects predictive of eventual addiction may include stimulation and other experiences not typically associated with opioids. Copyright (c) 2008 APA, all rights reserved.