'Addiction' supplement December 2002. "Treatment of marijuana disorders". Edited by Michael L. Dennis and Thomas F. Babor.
Dear Colleagues,
This edition of Addiction on cannabis is most unusual in several respects, for a scientific journal. Least controversial is that 'cannabis', the normal scientific term, is used interchangeably with the American intrusive term 'marijuana' which should probably now be avoided in serious research writing. Further, some authors appear to assume that cannabis use automatically warrants the term 'disorder' and still further that this is requires treatment in a high proportion of cases. This Addiction 'special issue' was 'made possible by the Center for Substance Abuse Treatment (CSAT) ... US Department of Health and Human Services'. This sort of patronage of a scientific journal is unusual in my experience. I do not know whether 'special editions' or 'supplements' as such are peer reviewed in the normal way.
The two introductory pieces, each including the contributing 'guest editors' (one being a regular Addiction regional editor), repeatedly emphasise the importance and prevalence of cannabis problems and thus the crucial place of good research and translating this into clinical practice. One can only agree. It is only in the third last paragraph of these 15 pages that they concede that existing treatment for cannabis dependence is associated with smaller reductions in drug use than with other drugs, and, especially in adolescents and young adults "in some cases actually increase their [cannabis] use". This important latter statement is written in parentheses for no syntactical reason that I could detect.
Quite rightly, emphasis is given by the authors to the age of first use of cannabis and the likelihood of problems in later life. They state rather cumbersomely: "The likelihood of having tobacco or alcohol problems is highest (39% and 45% respectively) for adolescents who first tried these substances prior to age 15 and the rates decline with later onset. ... For cannabis and other drugs there is a very different pattern: the rate of problems is more than 60% among people who first used prior to age 15. Although the rates decline in the older onset age cohorts, they never fall below 50% for a given substance. (The two exceptions to this pattern are cocaine and heroin, which have a high risk of problems regardless of the age of first use)."
These authors make a bold statement, then contradict it parenthetically for two of the most troublesome drugs in that country. "Never" usually means 'never'. But not, evidently, when followed by a sentence put in parentheses. This subject is too important to use less-than-accurate unscientific or ill defined language. We should use clear, correct and importantly, unemotional language when addressing one of the major problems facing modern society, being drug use in young people. We know that a scientific approach to any subject is more likely to result in optimal outcomes ... be it drug treatment, population control, HIV/AIDS, malaria programs or other endeavours. There are a number of important inconsistencies in this issue of Addiction.
There appear to be unwritten assumptions about cannabis use and its dangers in a section entitled "Beyond Benign Neglect". Referring to those in whom treatment was 'mandated', the authors state: "Even those who are not cannabis-dependent demonstrate a wide range of functional impairment (eg. missing work, school, fighting, arrests, injuries) that varies with their frequency of using cannabis use." Apart from awkward English, this would seem to imply that cannabis use is often associated with delinquency and perhaps (but without any references) in a *causative* manner.
These authors detail the widespread availability, relative cheapness and strength of cannabis in America, but there is only passing reference to the failure of legal sanctions to keep the drug out of the reaches of young people. It is a serious oversight to ignore good research from Holland, a comparable western country which has had virtually legal availability of cannabis for adults for over a generation. I cannot imagine any reason why serious, experienced researchers and commentators would choose to neglect such a major source of evidence on cannabis harms.
There is still a major problem with terminology when some authors consider cannabis use needful of treatment may consist of only weekly drug use episodes. True cannabis dependence is a problem and certainly needs all of our efforts as professionals in the field. But some would consider a program which sought to address once weekly cannabis use in teenagers as rather 'low-priority' in the scheme of drug related harms, and when compared against the major problems of hepatitis C, overdose, depression and dependence (not to mention bush fires and terrorism).
Dennis and colleagues describe the Cannabis Youth Treatment (CYT) experiment in the first research report in this Addiction supplement. They randomly assigned young people referred from a variety of agencies to be treated with one of five behavioural therapies including CBT and family therapy. But when describing 'existing practice' for 150,000 adolescents treated in 1998, it is stated that half used the drug only weekly. It is hard to take the rest of their work seriously when they are 'treating' a large proportion of young people who may not qualify for a DSM IV category for either abuse or dependence.
Dennis and co-authors stress that they were anxious to be able to generalise their results to the American community. It is disappointing, therefore, that they excluded 44% of 1250 referrals on a number of criteria. These included those who (i) had used other drugs/alcohol to a significant degree (ii) had a substantial medical or psychological diagnosis, (iii) were intellectually impaired, (iv) had a severe conduct disorder or impending incarceration, (v) lacked an available English speaking parent. Another 15% declined to be involved while over half of those accepted felt that they did not need treatment for cannabis use. About two thirds were coerced by the American judicial system making the results less meaningful scientifically in other jurisdictions such as Canada, UK or Australia. Fully 80% did not view their cannabis use as 'a problem'. Only 45% were classified as cannabis dependent, yet we are given the intriguing information that this figure rises to 76% if the parents' opinions are included (!).
Self report of cannabis use in the previous month at intake, three and six months was 83%, 59% and 58%. On-site urine testing performed at the same intervals was positive for 76%, 68% and 71%. These hardly give rise to great optimism for the five programs being trialed. Nor is any statistical significance given for these modest and seemingly unimpressive, if downward, trends. No explanation is given for the remarkable finding that up to a quarter of the enrolled subjects were not actually using cannabis at or near the start of 'treatment' by either self report or urine test.
Therapy sessions were taped and reviewed with which some may find a fundamental ethical discomfort. Retention is incompletely reported, eg. 81% completed 2 months or more of a 3 month program (mean 80 days). The average stay in a 5-6 week treatment was 43 days which seems unlikely if not impossible unless there were 'overstayers'. To the credit of these researchers, it appears that over 90% of subjects were interviewed at 3, 6, 9 and 12 months using various extensive means of contact.
With high expectations I read on to find that these researchers, who repeatedly stressed the importance of their work, give no outcome results despite their comparative 'manual' intervention 'treatment phase' ending over two years ago. They whet our appetite by stating that after some preliminary results reported here, "more will be forthcoming in the coming years". Of the copious references fully 37 are from these authors themselves and their own institutions, showing their publishing prowess and perhaps also just how small the cannabis 'treatment' field actually is.
In this special issue of Addiction there follows a series of 6 "research reports", mostly from the same stable of authors as the initial report and involving one or both guest editors. These mostly document various aspect of the conduct of the same study of 600 American teenagers who chose to use cannabis and came to attention of the treatment fraternity. Once again, the wider field is not always considered in most of these, notably the item on costs which omits to compare the cost of legal sanctions which are the primary option used in some countries for drug control amongst their citizenry. The second part of this Supplement is devoted to the Marijuana Treatment Project looking at long term cannabis users and three treatment interventions. Sadly, this is just a description of the trial (including an interesting 'delayed treatment control') but again, no outcome results!
Considering the widespread use of cannabis and its propensity to cause problems in some users, especially young people, research of this nature is very important. However it is most unusual to publish details and proposals in peer reviewed journals before results are collated. Surely it is putting the cart before the horse - especially when some such programs have shown little, or even negative impact on drug use in the past. Some of the subjects are probably normal adolescents and the chance of 'treatment' improving their outcomes is simply not a consideration. The decision to omit the "no treatment" or 'control' option for treatment interventions was taken for stated reason that "past studies have shown consistently that untreated or minimally treated adolescents become worse or fail to improve". Many would disagree with this deduction and some may even find it spurious. Without controls the rigour of any study is reduced, which is very disappointing for a large, prospective intervention such as this.
comments by Andrew Byrne ..
citations:
Dennis M, Titus JC, Diamond G, Donaldson J, Godley SH, Tims FM, Webb C, Kaminer Y, Babor T, Roebuck MC, Godley MD, Hamilton N, Liddle H, Scott CK & CYT Steering Committee. The Cannabis Youth Treatment (CYT) experiment: rationale, study design and analysis plans. Addiction (2002) 97 (Suppl )1 16-34
Stephens RS, Babor TF, Kadden R, Miller M. Marijuana Treatment Project (MTP). Addiction (2002) 97 (Supp )1 109-124
