Cannabis is the most commonly used illicit drug in Canada [1Ogborne AC, Smart RG. Cannabis users in the general Canadian population Subst Use Misuse 2000; 35: 301-11.]. There are clear negative consequences to the use of Cannabis from a health and psychosocial perspective [2Hall W. The health risks of cannabis Aust Fam Physician 1995; 24: 1237-40., 3Hall W. The respiratory risks of cannabis smoking Addiction 1998; 93: 1461-3.]. Primarily, Cannabis displays a clear dose-response curve in which the more frequently people use Cannabis, the more likely they are to experience negative consequences from this use [4Cunningham JA, Bondy SJ, Walsh GW. The risks of cannabis use: Evidence of a dose-response relationship Drug Alcohol Rev 2000; 19: 137-42.]. In addition, there is an accumulating body of evidence on the connection cannabis use to the onset of schizophrenia among vulnerable populations [5Moore TH, Zammit S, Lingford-Hughes A, et al. Cannabis use and risk of psychotic or affective mental health outcomes: a systematic review Lancet 2007; 370: 319-28.].

A particular concern with Cannabis is that it is a drug most often used by young adults [6Macleod J, Oakes R, Copello A, et al. Psychological and social sequelae of cannabis and other illicit drug use by young people: a systematic review of longitudinal, general population studies Lancet 2004; 363: 1579-88.]. As a means of harm reduction amongst this population, a recent Canadian initiative developed a website called ‘What’s with weed?’ (www.WhatsWithWeed.ca) [7Sanagan P. Up in smoke? The Challenges of cannabis for health promotion. Ontario Public Health Association eBulletin Available from: http://www.ohpe.ca/ebulletin/index.php?option=com_content&task=view&id=10262&Itemid=78 2009 [cited 9 February 2009];]. The website focuses on young adults, takes a harm reduction perspective, and allows the participant to make an informed choice about their Cannabis use. The Internet is an excellent method for providing this service to young adults, given the high proportion of teenagers who use the Internet on a regular basis, the low cost of providing the service once it is developed, and the anonymous nature of the website [8Cunningham J. Is level of interest among cannabis users in self-help materials and other services aimed at reducing problem use? Addiction 2005; 100: 561-2., 9Cunningham JA, Selby PL, Kypri K, Humphreys KN. Access to the Internet among drinkers, smokers and illicit drug users: Is it a barrier to the provision of interventions on the World Wide Web? Med Inform Internet Med 2006; 31: 53-8.].

A new tool commissioned for this website is the Check Your Cannabis (CYC) screener. This screener allows the participant to answer a few questions about their cannabis use and then receive personalized feedback about how their Cannabis use compares to others of the same age and sex and also, provides a test of the severity of the participant’s cannabis use. The goal of the CYC screener is to allow participants to evaluate their own Cannabis use in a non-judgmental setting and with a harm reduction perspective. To our knowledge, this is the first screener of its type for Cannabis users. The CYC screener was developed within the context of the literature on the benefits of normative feedback (i.e., providing a comparison of how much the participant consumes to how much others consume). While no published work exists to-date that demonstrates the benefits of normative comparisons for Cannabis users, there is a growing body of evidence on the impact of normative feedback on heavy drinkers, smokers, and even problem gamblers [10Neighbors C, Larimer ME, Lewis MA. Targeting misperceptions of descriptive drinking norms: efficacy of a computer-delivered personalized normative feedback intervention J Consult Clin Psychol 2004; 72: 434-7.-12Cunningham JA, Hodgins DC, Toneatto T, Rai A, Cordingley J. Pilot study of a personalized feedback intervention for problem gamblers Behav Ther 2009. (in press)].

The intent of this brief report is to describe the content of the CYC screener as well as the characteristics of the users of this screener in the first 12 months of its existence. In addition, comparisons will be made between the version of the CYC linked to the What’s With Weed website to a stand alone version (www.CheckYourCannabis.net).

There were 986 completed CYC tests in the first year of use, 901 from the What’s With Weed site and 85 from the standalone site. Almost two thirds (58.8%, N = 580) stated that they were taking the test for themselves, while 8.7 (n = 86) said they were taking the test for someone else and 32.5% (n = 320) said they were just checking out the test to see what the results looked like. There was no significant difference (p > .05) in the proportion of participants who said they were taking the test for themselves between the two versions of the websites. The remaining results will only use data from the 580 tests where participants said they were taking the test for themselves (539 tests from the What’s With Weed site and 41 from the standalone version).

There were no significant differences (p > .05) in the proportion of male versus female participants in the two websites with 73.3% being male in the full sample (n = 580). However, there were significant differences in age and country of residence between the two websites with participants using the What’s With Weed website being younger and more likely to reside in Canada as compared to the standalone version (Mean [SD] Age = 20.4 [7.2] and 29.7 [12.4] respectively; t-test = 4.7, p = .001; Proportion residing in Canada = 90.4% versus 63.4% respectively; χ² = 24.5, 1 df, p < .001). Table 1 presents the demographic and Cannabis use characteristics for the participants of the two websites.

Table 1

Demographic and Cannabis Use Characteristics of Users of Two Different Versions of the Check Your Cannabis Screener Website

There were no significant differences (p > .05) in frequency and severity of Cannabis use reported on the two websites. For the combined sample (n = 580), 23.8% were categorized as high risk, 70.3% as moderate risk, and 5.9% as low risk Cannabis users on the ASSIST scale. Frequency of Cannabis use was fairly high, with 50.0% reporting daily or almost daily Cannabis use in the last three months (24.5% weekly use and 25.5% reporting less than weekly use). Finally, 41.3% reported spending $100 per month or more on Cannabis use and 22.1% reported spending more than $100 on one occasion at least once in the last 12 months.

The CYC provides participants with objective personalized feedback about their Cannabis use in a non-judgemental fashion. Participants of the website appeared to be frequent Cannabis users with moderate severity risk associated with their Cannabis use. One clear result from this study is the benefit of linking the screener to an already established website (What’s With Weed). The standalone version was not advertised and was rarely used. In contrast, the What’s With Weed version was used roughly ten times as often. In addition, linking to the What’s With Weed site allowed targeting of the most relevant population – young Canadians (as only Canadian comparison data was available at the time of this study).

In designing the CYC screener, we were cognizant of the need for brevity as many users of the Internet tend to skip quickly from one page to another [17Danaher BG, McKay HG, Seeley JR. The information architecture of behavior change websites J Med Internet Res 2005; 7: e12.]. The CYC screener also took advantage of the availability of excellent population normative data that is available for use in Canada [14Statistics Canada. Canadian Tobacco Use Monitoring Survey, CTUMS Available from: http://www.hc-sc.gc.ca/hl-vs/tobac-tabac/research-recherche/stat/ctumsesutc_2006_e.html 2006 [cited 2 January 2008];] and is also profiting from the availability of large, high quality data sets in the USA [15Substance Abuse and Mental Health Services Administration. Results from the 2002 National Survey on Drug Use and Health: Detailed Tables Available from: http://oas.samhsa.gov/nsduh/reports.htm#Standard 2003 [cited, 7 April, 2009];]. As normative data is added to the CYC from other countries it will be a challenge to find sufficiently large general population data sets that will allow the generation of accurate population summary data, separately for males and females, and for different age groups. In addition, the development of screeners, such as the ASSIST, by the World Health Organization has allowed for the inclusion of a brief, research-validated assessment that is relevant for participants in many different cultural settings [13Humeniuk R, Ali R, Babor TF, et al. Validation of the alcohol, smoking and substance involvement screening test (ASSIST) Addiction 2008; 103: 1039-47.].

Personalized feedback screeners, as well as other Internet-based interventions, have the goal of increasing the accessibility of services for those with addictions and other health concerns. Access to the Internet is widespread [18Internet World Stats. Internet World Stats: Usage and Population Statistics Available from: http://www.inter networldstats.com/stats14.htm 2009 [cited 2/11/2009];] and many people turn to the Internet for health information [19Fox S. The engaged e-patient population: People turn to the internet for health information when the stakes are high and the connection fast Available from: http://www.pewinternet.org/pdfs/PIP_Health_Aug08.pdf 2008 [cited 11 February, 2009];]. Many people with addictions concerns are unwilling or unable to access treatment and often cite reasons such as stigma or embarrassment, or the desire to deal with the problem on their own, as reasons for not seeking treatment [20Cunningham JA, Sobell LC, Sobell MB, Agrawal S, Toneatto T. Barriers to treatment: Why alcohol and drug abusers delay or never seek treatment Addict Behav 1993; 18: 347-53., 21Grant BF. Barriers to alcoholism treatment: Reasons for not seeking treatment in a general population sample J Stud Alcohol 1997; 58: 365-71.]. There is some evidence that Internet-based interventions are able to provide help to those traditionally underserved by face-to-face addictions treatment services [22Humphreys K, Klaw E. Can targeting nondependent problem drinkers and providing internet-based services expand access to assistance for alcohol problems? A study of the moderation management self-help/mutual aid organization J Stud Alcohol 2001; 62: 528-32.]. The challenge then, is to continue to expand the range and accessibility of these online services in order to provide help to more people in need.

Future directions for the Check Your Cannabis screener will be to address some of the clear limitations of this preliminary report. Primarily, research is needed to develop an evidence base regarding any impact on Cannabis use from taking the screener and to establish the reliability of the self-report data on this website. In addition, population comparison data will be added for more countries in order to make this globally accessible tool more relevant to all potential participants.

Dr. Cunningham has acted as a paid consultant to Evolution Health Systems Inc., the owner of the Check Your Cannabis software platform. Mr. van Mierlo is the CEO of Evolution Health Systems Inc.