writing prescriptions for themselves or by dive rting opioids that have been prescribed for
patients or from pharmacy supplies. Most individuals with opioid use disorder have
significant levels of tolerance and will experience withdrawal on abrupt discontinuation
of opioid substances. Individuals with opio id use disorder ofte n develop conditioned
responses to drug-related stimuli (e.g., cr aving on seeing any he roin powder–like sub-
stance)—a phenomenon that occu rs with most drugs that cause intense psychological
changes. These responses probably contribute to relapse, are difficult to extinguish, and typ-
ically persist long after detoxification is completed.