Effects of baclofen and mirtazapine on a laboratory model of marijuana withdrawal and relapse.
BACKGROUND
Only a small percentage of individuals seeking treatment for their marijuana use achieves sustained abstinence, suggesting more treatment options are needed.


OBJECTIVE
We investigated the effects of baclofen (study 1) and mirtazapine (study 2) in a human laboratory model of marijuana intoxication, withdrawal, and relapse.


METHODS
In study 1, daily marijuana smokers (n = 10), averaging 9.4 (+/-3.9) marijuana cigarettes/day, were maintained on placebo and each baclofen dose (60, 90 mg/day) for 16 days. In study 2, daily marijuana smokers (n = 11), averaging 11.9 (+/-5.3) marijuana cigarettes/day, were maintained on placebo and mirtazapine (30 mg/day) for 14 days each. Medication administration began outpatient prior to each 8-day inpatient phase. On the first inpatient day of each medication condition, participants smoked active marijuana (study 1: 3.3% THC; study 2: 6.2% THC). For the next 3 days, they could self-administer placebo marijuana (abstinence phase), followed by 4 days in which they could self-administer active marijuana (relapse phase); participants paid for self-administered marijuana using study earnings.


RESULTS
In study 1, during active marijuana smoking, baclofen dose-dependently decreased craving for tobacco and marijuana, but had little effect on mood during abstinence and did not decrease relapse. Baclofen also worsened cognitive performance regardless of marijuana condition. In study 2, mirtazapine improved sleep during abstinence, and robustly increased food intake, but had no effect on withdrawal symptoms and did not decrease marijuana relapse.


CONCLUSIONS
Overall, this human laboratory study did not find evidence to suggest that either baclofen or mirtazapine showed promise for the potential treatment of marijuana dependence.
Department of Psychiatry, Division on Substance Abuse, New York State Psychiatric Institute, 1051 Riverside Drive, Unit 120, New York, NY 10032, USA. mh235@columbia.edu
Margaret
M
Haney
Carl L
CL
Hart
Suzanne K
SK
Vosburg
Sandra D
SD
Comer
Stephanie Collins
SC
Reed
Ziva D
ZD
Cooper
Richard W
RW
Foltin
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000328:Adult; D000339:Affect / Q000187:drug effects; D001418:Baclofen / Q000008:administration & dosage / Q000494:pharmacology*; D003071:Cognition / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004435:Eating / Q000187:drug effects; D018755:GABA Agonists / Q000008:administration & dosage / Q000494:pharmacology; D006801:Humans; D008297:Male; D002189:Marijuana Abuse / Q000534:rehabilitation*; D008803:Mianserin / Q000031:analogs & derivatives* / Q000494:pharmacology; D000078785:Mirtazapine; D055502:Secondary Prevention; D012907:Smoking / Q000453:epidemiology; D013375:Substance Withdrawal Syndrome / Q000534:rehabilitation*; D055815:Young Adult
D000317:Adrenergic alpha-Antagonists; D018755:GABA Agonists; D008803:Mianserin; D000078785:Mirtazapine; D001418:Baclofen