Studies of Opioid Seeking Behavior: Yohimbine and Hydrocortisone Effects
Condition: Heroin Dependence; Opioid-Related Disorders
MeSH terms: Opioid-Related Disorders; Heroin Dependence
Study type: Observational

Summary: 
      This research deals with behaviors that are part of opioid dependence. The purpose is to
      study the extent to which stress and other factors, including money and amount of work
      effort, affect opioid choice. Specifically, the investigators will examine the effects of
      three issues/factors. The first is how hard participants are willing to work to obtain an
      opioid drug; the second is how much opioid drug would participants choose instead of money;
      and the third factor is how much participant's opioid drug choices are influenced after they
      are administered the drugs yohimbine and hydrocortisone, both of which could produce
      stress-like symptoms.
    

Detailed description: 
      Phase 1: Participants will first be an outpatient and must come to the Tolan Park Medical
      Building daily to receive buprenorphine doses. This phase will last at least 10 days or
      longer. Three times per week during the first two weeks (i.e., on 6 different days),
      participants will be asked to provide urine samples and to complete questionnaires that ask
      about opiate withdrawal symptoms.

      Phase 2: Participants will then live on an inpatient research unit (located in Detroit
      Michigan) for at least 16 consecutive nights and possibly up to 18 consecutive nights.
      Participants will continue on the same dose of buprenorphine as in phase 1.

      During this stay they will participate in a total of 11 experimental sessions. Participants
      will take part in multiple trials in which they have the opportunity to choose drug,
      hydromorphone, or money. Hydromorphone is a heroin-like opioid. During the first two test
      sessions, participants will receive a sample of the drug doses that can be chosen. Before
      each of the final 9 test sessions begin, participants will be given a capsule containing
      either different doses of the drug yohimbine or a placebo (blank). Yohimbine is a drug that
      has been shown to produce a "stress"-like response in humans. Then participants will be given
      a capsule that contains either different doses of the drug hydrocortisone or a placebo
      (blank). Hydrocortisone is also a drug that can produce a "stress"-like response in humans.
      Then participants will have the opportunity to choose either drug or money by using a
      computer to earn choices. Respiration rate, oxygen saturation, heart rate, and blood pressure
      will be monitored throughout choice trials. Self-report questionnaires will be completed at
      different times during the study.

      Phase 3: After participants have completed the experimental procedures, they will again come
      to the Tolan Park Medical Building daily to receive buprenorphine doses. The dose of
      buprenorphine will be gradually decreased so that they will eventually be free from
      medication. This will take three weeks. We will administer questionnaires and collect urine
      samples three times each week.
    

Observational model: Case-Only
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Heroin dependent research volunteers
      
Keywords: Behavioral Economics; Drug self administration; Opioid