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- From: Jim Rosenfield <jnr@igc.apc.org>
- Newsgroups: talk.politics.drugs
- Date: 14 Oct 94 20:39 PDT
- Subject: Alcohol + MJ Toxicology
- Message-ID: <1484000762@cdp>
-
- From: Jim Rosenfield <jnr>
-
- Found this on the DRUGABUS list, am reposting here for your use:
-
-
- Hmmm, time to come out of lurker mode. Here's the executive summary from a
- 1986 study -
-
- The Interaction Between Alcohol and Marijuana
- A Dose Dependent Study of the Effects on Human Moods and Performance Skills
-
- By
- Gregory B. Chesher
- Helen Dauncey
- John Crawford
- Kim Horn
-
- Psychopharmacology Research Unit
- Department of Pharmacology
- University of Sydney, NSW.
-
- for the Federal Office of Road Safety (Australia)
-
- Executive Summary
- =================
-
- 1. A study was designed to examine the effects of marijuana and alcohol when
- taken alone and in combination on human skills performance and mood.
-
- 2. Four dosage conditions were employed for each drug (placebo and three
- active doses). All possible combinations of these dosage conditions were
- tested (ie 16 dosage groups).
-
- 3. Twenty subjects were used for each dosage group, the experiment employing
- 320 subjects in all. Each subject attended the laboratory on one occasion
- only.
-
- 4. Data collected were for psychomotor performance using a battery of
- computer-presented tests, mood effects, subjective assessments of the nature
- and degree of intoxication, and the subjective assessment of the effects of
- the drugs on driving skills and willingness to drive a motor vehicle.
-
- 5. The performance battery included tests of human skills related to those
- considered necessary to drive a motor vehicle with safety.
-
- 6. The population sample were recruited by advertisements on two Sydney
- "Rock music" FM radio stations. All volunteers were non-naive as regards
- marijuana use and were indeed heavy to very heavy users of this drug. The
- extent of alcohol use by the volunteers was considered to be within the
- normal range of use of this drug within the community.
-
- 7. The attitudes expressed concerning the dangers associated with the use of
- the two drugs indicated that the population sample was heavily biased
- against alcohol and in favor of marijuana
-
- 8. The subjective assessment of the doses of each drug employed indicated
- that they were comparable. The subjects assessed the degree of intoxication
- by marijuana as being of a similar intensity as that produced by alcohol.
- The doses selected therefore appear to be relevant to those used within the
- social experience of the volunteer population
-
- 9. Both drugs produced significant dose-dependent effects on the performance
- measures, on the intoxication rating scales and on some of the mood
- measures.
-
- 10. However, there were both quantitative and qualitative differences
- between these effects, both on the performance measures and on the
- subjective mood effects of the two drugs.
-
- 11. By far the major effects on these tests were those produced by alcohol.
-
- 12. The effect on skills performance of alcohol and marijuana when taken in
- combination was essentially one of addition. Marijuana tended to increase
- the intensity of the performance impairment produced by alcohol. However
- there was evidence to suggest that the lowest dose of marijuana produced a
- degree of antagonism of the effects of alcohol.
-
- 13. Marijuana had no effect on the absorption or metabolism of alcohol. The
- blood alcohol concentration was not affected by any of the doses of
- marijuana used.
-
- 14. The results of this study indicate clearly that alcohol and marijuana
- are distinctly different drugs. The effects produced on the performance
- measures were qualitatively and quantitatively different. In addition, the
- differences in the nature of the drug-induced subjective intoxication and
- the self-reported changes in mood effects such as anxiety and alertness,
- strongly suggested different drug actions.
-
- 15. The ability to discriminate and assess the degree of intoxication with
- alcohol was not affected by marijuana. However, the ability to assess the
- intoxication due to marijuana was greatly affected by alcohol. The
- subjective intoxication produced by marijuana appears to be of a more subtle
- nature than that produced by alcohol.
-
- 16. Evidence is presented which suggests that under the influence of
- alcohol, subjects engage in a "speed-accuracy trade-off". They are prepared
- to make a hasty response to a question rather than to spend more time to
- ensure a correct answer. This effect could be related to a risk-taking
- behaviour. The results with marijuana on the other hand suggested a slower
- and more careful approach to the problem, though as with alcohol, an
- increased error rate in responses was recorded.
-
- 17. Evidence is presented which suggests that marijuana produces periodic
- attentional lapses.
-
- 18. The results strongly suggest that the performance deficits and mood
- changes produced by alcohol are of a greater magnitude than those produced
- by marijuana.
-
- 19. Recommendations for directions of further research are made
-
- ----------------------
-
- whhheeeeewwww, apologies for the long post, but at least there won't be 30
- replies asking for methodology, numbers, etc etc. (email privately for
- specifics!!!). Anyway, basically mj impairs driving, but not as much as
- alcohol. As for the NTSA study, I do wonder about the methodology. Exposure
- is obviously going to be a major factor and there is little doubt that there
- are more people using alcohol than mj, so of course there will be more
- alcohol related accidents (or did they control for this? - I haven't read
- it). I also suspect that people who have been drinking may be more likely to
- drive afterwards than people using mj. In any case legalisation of more
- drugs (which I am *for* incidentally) will require cheap accurate techniques
- for measurement of levels of intoxication to allow enforcement of any
- restrictions (eg don't smoke and drive). IMHO, this perhaps is one of the
- few legitimate anti-legalisation arguments.
-
- David
- davids@gpo.pa.uq.oz.au
-
- David Steadson, Senior Research Assistant
- Social and Preventive Medicine, University of Queensland
- Brisbane, Australia.
-
-
-
-