The THC content of cannabis in Australia: evidence and implications

Hall, Wayne; Swift, Wendy

doi:10.1111/j.1467-842x.2000.tb00500.x

Cited by 55 publications

(45 citation statements)

References 25 publications

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“…The fact that CanDep included respondents with a wider range in frequency of use cannot explain these contrasting results, as no difference in cannabis use patterns was observed in the daily cannabis users in our sample. However, the larger difference in number of joints per day between dependent and non-dependent users found by Looby et al (0.35 joints compared to 0.2 joints in the current study) may actually correspond to similar delta9-tetrahydrocannabinol (THC) exposure, considering that the concentration of THC in Dutch marijuana is, on average, twice as high as Australian marijuana [56,57]). An alternative explanation could be that the differences in cannabis use between the non-dependent and dependent daily cannabis users in the study by Looby et al were significant, but that the effect sizes were all somewhat small (standardized effect sizes ranging from 0.17 to 0.27), and that our study was not able to detect these small (clinically irrelevant) differences.…”

Section: Cannabis Use In Dependent and Non-dependent Frequent Usersmentioning

confidence: 59%

Mental health differences between frequent cannabis users with and without dependence and the general population

et al. 2013

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Mental health differences between frequent cannabis users with and without dependence and the general population van der Pol, P.; Liebregts, N.; de Graaf, R.; ten Have, M.; Korf, D.J.; van den Brink, W.; van Laar, M. Published in: Addiction DOI:10.1111/add.12196 Link to publicationCitation for published version (APA): van der Pol, P., Liebregts, N., de Graaf, R., ten Have, M., Korf, D. J., van den Brink, W., & van Laar, M. (2013). Mental health differences between frequent cannabis users with and without dependence and the general population. Addiction, 108(8), 1459-1469. DOI: 10.1111/add.12196 General rightsIt is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. ABSTRACTAims To compare the prevalence of mental disorders between frequent cannabis users with and without dependence and the general population. Design Cross-sectional comparison of interview data. Setting Enriched community sample of frequent cannabis users and a representative sample of non-users and non-frequent users from the general population. Participants A total of 521 young adult (aged 18-30 years) frequent cannabis users, 252 of whom were with DSM-IV cannabis dependence (D+) and 269 without DSM-IV cannabis dependence (D-), and 1072 young adults from the general population. Measurements Multinomial logistic regression was used to compare groups regarding the presence of DSM-IV mental disorders. Detailed measures of cannabis use, childhood adversity and other substance use were considered confounders. Findings Compared with the general population, externalizing disorders were more prevalent in D-[odds ratio (OR) = 8.91, P < 0.001] and most prevalent in D+ (OR = 17.75, P < 0.001), but internalizing disorders were associated only with D+ (mood OR = 4.15, P < 0.001; anxiety OR = 2.20, P = 0.002). Associations were attenuated (and often became non-significant) after correction for childhood adversity and substance use other than cannabis. However, the prevalence of mental disorders remained higher in D+ compared with D-(OR = 2.40, P < 0.001), although cannabis use patterns were remarkably similar. Conclusions Cannabis use patterns, childhood adversity and the use of other substances are similar in dependent and non-dependent frequent cannabis users. With the exception of more externalizing disorders, the mental health ...

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Section: Cannabis Use In Dependent and Non-dependent Frequent Usersmentioning

confidence: 59%

Mental health differences between frequent cannabis users with and without dependence and the general population

et al. 2013

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“…Consequently, the cannabis users within our groups did not have a long history of cannabis use (average 5.3 years). To ensure no heavy cannabis users were included in our analysis, a conservative cutoff was selected and individuals who consumed more than 14 cones per week (from our estimates, approximately 0.9 g cannabis plant matter, or approximately 36 mg THC; Hall and Swift, 2000) were excluded from the study. One individual was excluded on these criteria.…”

Section: Participantsmentioning

confidence: 99%

Saccade and Cognitive Function in Chronic Kava Users

Cairney

Clough

Maruff

et al. 2003

Neuropsychopharmacol

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Kava is an extract from the Piper methysticum Forst. f. plant that has been consumed in the Pacific islands for millennia and more recently, among indigenous populations, in northern Australia and throughout the Western world as an herbal medicine. Through alterations on neuronal excitation, kava induces muscle relaxation, anasthesia, and has anxiolytic properties. There have been several isolated reports of psychotic syndromes, severe choreoathetosis and possible seizures following kava use. However, there is no conclusive evidence that kava interferes with normal cognitive processes. We tested a group of current, ex, and nonkava users among an indigenous population in northern Australia, using saccade and cognitive tests that have proven cross-cultural validity and are sensitive to subtle disruptions of the brain arising from substance abuse or neuropsychiatric illness. Despite collecting data from among the heaviest reported kava drinkers in the world, we found no impairment in cognitive or saccade function in individuals who were currently heavy kava users (and had been for up to 18 years), nor was there any impairment in individuals who had been heavy kava users in the past but had abstained for longer than 6 months. Current and ex-kava users showed a higher rate of kava dermopathy, lower body mass index, lowered blood lymphocytes and, in addition, current kava users showed elevated liver enzymes. While there has recently been increasing concern about potentially fatal liver damage attributed to kava use, we have found no evidence of brain dysfunction in heavy and long-term kava users.

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“…1997;Hall & Solowij 1997). There is also evidence that younger cannabis users are now using more potent forms of cannabis at an earlier age, thus increasing the amount of THC consumed, even though the actual concentration of THC in cannabis products has increased only marginally (Hall & Swift 2000).…”

Section: Prolonged Heavy Use Commencing At An Early Age Places Usersmentioning

confidence: 99%