• Ashtari, M., Avants, B., Cyckowski, L., Cervellione, K.L., Roofeh, D., Cook, P., Gee, J., Sevy, S., & Kumra, S. (2011). Medial temporal structures and memory functions in adolescents with heavy cannabis use. Journal of Psychiatric Research 45, 1055-1066.
• Casadio, P., Fernandes, C., Murray, R.M., & Di Forti, M. (2011). Cannabis use in young people: The risk for schizophrenia. Neuroscience and Biobehavioral Reviews 35, 1779-1787.
• De Petrocellis, L., Ligresti, A., Moriello, A.S., Allarà, M., Bisogno, T., Petrosino, S., Stott, C.G., & Di Marzo, V. (2011). Effects of cannabinoids and cannabinoid-enriched cannabis extracts on TRP channels and endocannabinoid metabolic enzymes. British Journal of Pharmacology 163, 1479-1494.
• Fakier, N. & Wild, L.G. (2011). Associations among sleep problems, learning difficulties and substance use in adolescence. Journal of Adolescence 34, 717-726.
• Groth, S.W. & Morrison-Beedy, D. (2011). Smoking, substance use, and mental health correlates in urban adolescent girls. Journal of Community Health 36, 552-558.
• Guindon, J. & Hohmann, A.G. (2011). The endocannabinoid system and cancer: Therapeutic implication. British Journal of Pharmacology 163, 1447-1463.
• Kirkbride, J.B. (2011). Incident cannabis use in adolescents and young adults is associated with an increased risk of developing psychotic symptoms. Evidence-based Mental Health 14, 70.
• Kozela, E., Lev, N., Kaushansky, N., Eilam, R., Rimmerman, N., Levy, R., Ben-Nun, A., Juknat, A., & Vogel, Z. (2011). Cannabidiol inhibits pathogenic T cells, decreases spinal microglial activation and ameliorates multiple sclerosis-like disease in C57BL/6 mice. British Journal of Pharmacology 163, 1507-1519.
• Legleye, S., Janssen, E., Beck, F., Chau, N., & Khlat, M. (2011). Social gradient in initiation and transition to daily use of tobacco and cannabis during adolescence: A retrospective cohort study. Addiction 106, 1520-1531.
• Milman, G., Barnes, A.J., Schwope, D.M., Schwilke, E.W., Goodwin, R.S., Kelly, D.L., Gorelick, D.A., & Huestis, M.A. (2011). Cannabinoids and metabolites in expectorated oral fluid after 8 days of controlled around-the-clock oral THC administration. Analytical and Bioanalytical Chemistry 401, 599-607.
• Pahl, K., Brook, J.S. & Koppel, J. (2011). Trajectories of marijuana use and psychological adjustment among urban African American and Puerto Rican women. Psychological Medicine 41, 1775-1783.
• Parker, L.A., Rock, E.M. & Limebeer, C.L. (2011). Regulation of nausea and vomiting by cannabinoids. British Journal of Pharmacology 163, 1411-1422.
• Prince van Leeuwen, A., Creemers, H.E., Greaves-Lord, K., Verhulst, F.C., Ormel, J., & Huizink, A.C. (2011). Hypothalamic-pituitary-adrenal axis reactivity to social stress and adolescent cannabis use: The TRAILS study. Addiction 106, 1484-1492.
• Rentzsch, J., Buntebart, E., Stadelmeier, A., Gallinat J., & Jockers-Scherübl M.C. (2011). Differential effects of chronic cannabis use on preattentional cognitive functioning in abstinent schizophrenic patients and healthy subjects. Schizophrenia Research 130, 222-227.
• Russo, E.B. (2011). Taming THC: Potential cannabis synergy and phytocannabinoid-terpenoid entourage effects. British Journal of Pharmacology 163, 1344-1364.
• Sagredo, O., Pazos, M.R., Satta, V., Ramos, J.A., Pertwee, R.G., & Fernández-Ruiz, J. (2011). Neuroprotective effects of phytocannabinoid-based medicines in experimental models of Huntington's disease. Journal of Neuroscience Research 89, 1509-1518.
• Schubart, C.D., Sommer, I.E., van Gastel, W.A., Goetgebuer, R.L., Kahn, R.S., & Boks, M.P. (2011). Cannabis with high cannabidiol content is associated with fewer psychotic experiences. Schizophrenia Research 130, 216-221.
• Storr, C.L., Wagner, F.A., Chen, C.Y., & Anthony, J.C. (2011). Childhood predictors of first chance to use and use of cannabis by young adulthood. Drug and Alcohol Dependence 117, 7-15.
• Thompson, R.G. & Hasin, D.S. (2011). Cigarette, marijuana, and alcohol use and prior drug treatment among newly homeless young adults in New York City: Relationship to a history of foster care. Drug and Alcohol Dependence 117, 66-69.
• Vandrey, R., Smith, M.T., McCann, U.D., Budney, A.J., & Curran, E.M. (2011). Sleep disturbance and the effects of extended-release zolpidem during cannabis withdrawal. Drug and Alcohol Dependence 117, 38-44.

Media stories this issue

Each issue we will examine some of the cannabis-related stories that have received media attention across the country. The headlines are listed below in bold, with a short summary and/or commentary regarding the content of the news story beneath. If you are interested in obtaining a copy of a particular story, please contact Clare Chenoweth at c.chenoweth@unsw.edu.au

Newcastle addicts get help online

Newcastle Herald: August 1, 2011

A study conducted by Newcastle University’s Centre for Brain and Mental Health Research and the National Drug and Alcohol Research Centre has attracted “international interest after showing promising results.” The study is testing “computer and therapist treatments for people with heavy dependence on alcohol and/or cannabis” and has found that “computerised cognitive behavior therapy and motivational interviewing over three months elicited a better response than supportive counseling.” Senior Research Fellow Frances Kay-Lambkin said the research shows “great potential for computerised therapy.”

Sale of synthetic cannabis restricted

ABC Northern Tasmania: August 1, 2011

Kronic has now been placed on the Tasmanian Government’s poisons schedule. There have been concerns about whether Kronic may “produce extreme reactions including severe hallucinations, heart palpitations and psychosis.”

Call to give kids drug lessons

The West Australian: August 15, 2011

Carmen Acosta, Acting State Director of the WA branch of Mission Australia, “wants more comprehensive drug education in primary schools as children as young as 10 dabble in alcohol and cannabis.” School-based programs “delivered at a younger age could help the small number of children vulnerable to such drugs… [and] would have the more widespread benefit of fortifying students against peer pressure in high school.” Cannabis and alcohol frequently cause difficulties for those using Mission Australia’s counseling and rehabilitation services, with 80 per cent of clients experiencing problems with these drugs.

Using facebook increases teenage drugging: study

International Business Times: August 25, 2011

According to a national survey of American attitudes on substance misuse, “time spent social networking increases the risk of teens smoking, drinking and using drugs”, including cannabis. Those teenagers who engage with websites such as Facebook, are twice as likely to use cannabis than teens who do not use social networking sites. The study results indicated that “half of teens who spend any time social networking in a given day have seen pictures of kids “drunk, passed out, or using drugs on these sites. However, the study found that 9 of 10 parents do not think teens spending time on social networking sites like Facebook are likelier to drink or use drugs.”

What do we know?

2010 National Drug Strategy Household Survey Results – cannabis

Key findings

• Cannabis use declined between 1998 and 2007, however between 2007 and 2010 the proportion of people in Australia who had used cannabis in the previous 12 months increased from 9.1% to 10.3%.
• The rise in recent use of cannabis was seen for males and females, as well as those aged 50–59 years and those living in New South Wales and Western Australia. Statistically significant increases in recent cannabis use were also seen among some subpopulation groups—those without post-school qualifications, students, those who were never married, and those in Major cities and Inner regional areas.
• Use of cannabis in the previous 12 months was highest in the Northern Territory (16.5%) and Western Australia (13.4%).
• The largest proportion of people who had used cannabis in the last 12 months had used it once or twice a year (34.6%), while 20.9% said they used it once a week or more (but not as often as daily).
• Most people who had used cannabis had got it from a friend or acquaintance (65.9%), and used it in a private home (86.7%).

Current use and trends over time

Over time (1995 to 2010), the proportion of people in Australia aged 14 years or older who had used cannabis in the previous 12 months has changed. More specifically:

• The number of people in Australia using cannabis increased from 1.6 million in 2007 to 1.9 million in 2010
• After peaking in 1998, the proportion of people who had recently used cannabis had been decreasing, but in 2010, it increased significantly from 2007, from 9.1% to 10.3%, an increase that was reflected for both males’ and females’ use
• In 2010, there was an increase in the proportion of people who had used cannabis recently in all age groups, though the only statistically significant increase was seen in those aged 50–59 years (from 3.8% in 2007 to 5.5% in 2010)
• Since 1998, recent cannabis use has generally decreased in the younger age groups, but either increased or remained stable for the older age groups (40 years or older).

Cannabis use, by sex

In 2010, it was estimated that about 1.9 million people aged 14 years or older had used cannabis in the previous 12 months, and more than 700,000 people had used it in the week before the survey. Females were less likely than males to have used cannabis at any frequency. Males were twice as likely as females to have smoked cannabis in the previous week (5.2% for males compared with 2.6% for females).

Cannabis use, by social characteristics

Cannabis use varies by demographic characteristics. Across Australia, for people aged 14 years or older, some population groups were more likely to report recent cannabis use than the general population. More specifically:

• Socioeconomic status, education, and remoteness classification had little influence on a person’s recent cannabis use.
• Unemployed people and students were more likely than other labour force categories to have used cannabis in the previous 12 months, and retirees were the least likely (1.8%), while those who were currently employed had the highest proportion of ex-users (34.1%) and the lowest proportion who had never used cannabis (54.4%).
• People who had never married were more than twice as likely to have recently used cannabis than those who were either married or divorced, separated or widowed (19.9% compared with 6.5% and 7.5%, respectively).
• After removing the effects of different age structures, Indigenous Australians were 1.6 times as likely as non-Indigenous Australians to have recently used cannabis.
• Those who identified as homosexual or bisexual were almost twice as likely to have used cannabis recently as those who identified as heterosexual (26.0% compared with 10.0%).

Cannabis and health

In 2010, there appeared to be a relationship between a person’s cannabis use and his or her mental health. For people in Australia aged 18 years or older:

• Those who had reported using cannabis in the previous 12 months (18.7%) or in the previous month (20.5%) were more likely to have been diagnosed or treated for a mental illness than people who had not used in the previous 12 months (11.3%).
• Those who had used cannabis in the previous month (19.1%) or previous 12 months (16.3%) were more likely to report high or very high levels of psychological distress compared with those who had not recently used cannabis (9.1%).
• Those who had used cannabis in the previous month were more likely to assess their health as fair or poor than those who had not used in the previous 12 months.

Frequency of use

In 2010, for people in Australia aged 12 or older who had used cannabis in the past 12 months:

• The most common frequency of use was once or twice a year (34.7%), with a further 13% of recent users reporting using cannabis every day.
• Those in older age groups were more likely to use cannabis once a month or more often (56.8% for those aged 40 years or more, compared with 31.2% for those aged 12–17 years).
• About half of users aged 30 years or older used cannabis once a month or more often, which was higher than the proportion for those aged 29 years or younger.
• For both male and female recent users (aged 14 years or older), the most common frequency of use was once or twice a year (30.0% and 42.3%, respectively), but males were more likely than females to use cannabis once a week, while females were slightly more likely to use every few months.

Source of supply

In 2010, 65.9% of recent users aged 14 years or older obtained their cannabis from a friend or acquaintance, while 20.8% obtained their cannabis from a dealer. Males obtained drugs from a dealer in larger proportions than females (22.9% and 17.3%, respectively), and were twice as likely to grow their own cannabis as females (5.3% compared with 2.6%).

Usual place of use

In 2010, for recent cannabis users aged 14 years or older, the most common place for using cannabis was in a private home (86.7%), followed by private parties (45.7%). With larger proportions of males using cannabis than females, males were more likely than females to use cannabis in various places. This difference was most notable in use at private parties (49.1% males, 39.9% females), public places (22.0% males, 16.0% females), and in a car (17.7% males, 12.0% females). There were no statistically significant differences in place of use between 2007 and 2010.

This information was sourced from the 2010 National Drug Strategy Household Survey Report:

Australian Institute of Health and Welfare. (2011). 2010 National Drug Strategy Household Survey report. Drug statistics series no. 25. Cat. no. PHE 145. Canberra: AIHW.

Recent use of cannabis, by people aged 14 years or older, by state/territory, 1998-2010