Exploring Hidden Populations: Recreational Drug Users

Birgit U. Stetina1, Reinhold Jagsch2, Cornelia Schramel3, Tamara Lederman Maman4, Ilse Kryspin-Exner5
1,2,3,4,5 Faculty of Psychology, University of Vienna, Vienna, Austria

Abstract

The heterogeneous group of recreational drug users is usually inconspicuous in society. These individuals do not regard themselves as drug users in a conventional way and therefore hardly can be reached through traditional methods (e.g. heavy drug user studies). The benefits of psychological online research were examined by exploring the “hidden” population of recreational drug users. An international cross-continental online study was carried out surveying 9,268 recreational drug users from English and German speaking countries. The data was obtained via internet and evaluated by means of statistical inference, descriptive and structure-finding procedures. The research population collected online seems to differ in many variables from the “usual” clinical study population (e.g. age, sex). Results indicate a great degree of trust in online information and a strong use of the data highway (more than 72%) for getting information on substances. Besides the widely known advantages of using the internet for psychological research, experiences show strong evidence that the internet may not only be a new but in many cases also better tool for research in special psychological fields.

Introduction

Recreational drug use is understood as the use of mind-altering substances for the purpose of altering one's mental state, typically without the supervision of a physician, mainly for direct or indirect pleasure. The use of substances for utilitarian purposes – such as the relief of fatigue or insomnia, or the control of appetite – is not understood as recreational. Besides the often used legal substances like alcohol and nicotine, many illegal drugs are also used recreationally. One of the emerging trends in the last 20 years was the rising use of the so-called club drugs. For example 3,4-methylendioxymethamphetamine (MDMA), known as ecstasy, penetrated diverse cultures to a large extent (Sessa & Nutt, 2007). The terminology “club drugs” is a bit confusing because on one hand the connection between recreational drug use and nightlife has been repeatedly demonstrated (Deehan & Saville, 2003; Hammersley, Ditton, Smith, & Short, 1999; Riley, James, Gregory, Dingle, & Cadger, 2001; Winstock, Griffiths, & Stewart, 2001). In addition it has been shown that the use of psychotropic substances is widespread everywhere under “clubbers“ or “ravers“ (Deehan & Saville, 2003; Tossmann, Boldt, & Tensil, 2001b). Especially for ecstasy, various studies came to the conclusion that this population has significantly more experience with drugs than the general population, with the most extreme data from England where 90% of clubbers use drugs, in comparison to 10% of young people in the general population (Arria, Yacoubian, Fost, & Wish, 2002; European Monitoring Center for Drugs and Drug Addiction, 2002; Tossmann, Boldt, & Tensil, 2001a). However, on the other hand the rates of consumption are not only due to this special population of ravers and clubbers. Indeed the proven correlation is, unlike the information above, not high enough to be considered causal for the increase of recreational drug consumption (Tossmann et al., 2001b).

The present article concentrates on the use of illegal club drugs, especially ecstasy, for recreational purposes. The prevalence of ecstasy use in the EU has been increasing since the 1990s. After cannabis, synthetic substances are the second most used illegal drugs and the users have a high affinity to other substances (European Monitoring Center for Drugs and Drug Addiction, 2007; Tossmann et al., 2001b). Numerous studies have pointed out that recreational and club drug consumers have an increasing tendency for polytoxicomanic use patterns (most often documented in combination with ecstasy) (Rodgers, 2000; Scholey et al., 2004; Winstock, Wolff, & Ramsey, 2002). New, and so far partly unknown, substances are in use (Schifano et al., 2005; Winstock et al., 2002).According to reports and the rising frequency in studies, the next emerging trend might be GHB and Ketamine (Degenhardt, Darke, & Dillon, 2002; Dillon, Copeland, & Jansen, 2003; European Monitoring Center for Drugs and Drug Addiction, 2007).

Recreational drug users do not regard themselves as consumers in a conventional way and most of them do not experience addiction (Cousto, 1999). With a low willingness to stop consumption, the users that seek help in drug centers are only those with severe problems (Schinnerl, Kriener, & Schmid, 2000; Siliquini, Morra, Versino, & Renga, 2005). Inconspicuous in society this special population cannot be reached like other “clinical” populations. However, this special population strongly uses the internet and the internet has already been identified as an important source of information for recreational drug users (Falck, Carlson, Wang, & Siegal, 2004; Stetina, Jagsch, & Kryspin-Exner, 2004). The internet is not only a primary source for consumers, also professionals and (official) organizations should go online to become aware of new drug trends. The developments in information and communication technologies support the diffusion of new trends (European Monitoring Center for Drugs and Drug Addiction, 2007). Innovative consumers use this source of information. Web sites that focus on recreational drugs convey all sorts of information from different perspectives (Boyer, 2005; Wax, 2002). An innovation is that users can order various substances through the internet, especially herbal drugs – this way, new possibilities emerge (Gijsbers & Whelan, 2004). The options of gathering information, expressing personal opinions or getting help or advice contribute to the emerging of new trends. Additionally, the internet as an e-commerce marketplace also speeds up the transmission of information or even the substances via online-shopping (Schifano, Leoni, Martinotti, Rawaf, & Rovetto, 2003). The WWW enables relatively anonymous business transactions across the world 24 hours a day. So the fluidity of cyberspace is ideally suited for illicit drug transactions (Forman, 2006). Schifano et al. (2006) explored data from web pages regarding information of consumption, production and sale of psychoactive substances. The authors reported that 42% of the websites showed a clear anti-drug position, 30.1% did not clearly state their view, 17.9% showed a pro-drug approach and 10% a harm reduction approach. 9.1% of the websites offered detailed information about the technical procedures to synthesize and extract a range of variant recreational psychoactive compounds. Also “no prescription web sites” have begun to emerge, which allows people to acquire drugs without a prescription. Little is known on how to control the “no prescription web sites”, therefore strategies will be needed to examine these new trading strategies (Forman, 2006).

Taking the obvious internet experience of recreational drug users, the mass of drug-related online information and the lack of other research methods to gain information about hidden populations into consideration, it seems a logical consequence to explore this inconspicuous population online. The best-known and so far biggest study on recreational drug users, which has been carried out as an online research, is the so-called Drugnet Study. In three periods, 1996, 1997 and 1998 it examined the potential of the internet to discover hidden populations, like those of recreational drug users. Additionally, it has been the first survey to observe explorative data to describe the hidden population of non-addicted recreational users of illegal substances. Data was collected from nearly 2,000 participants – this represents the biggest sample of non-addicted users of illegal substances ever. (Duncan, White & Nicholson, 2003; Nicholson, White, & Duncan, 1999; Nicholson, White, & Duncan, 1998; Reneau, Nicholson, White & Duncan, 2000). Another example of online-research with ecstasy consumers and persons who do not use ecstasy as target group took place in Great Britain and showed again the potential of web-based designs to gather information and study special populations. Information about polyvalent use patterns and memory abilities could be gathered from the data (Rodgers et al., 2003; Scholey et al., 2004).

The tremendous potential of the internet for explorative studies is clear looking at the legendary explorative online survey by Coomber (1997). The author made an investigation with drug dealers (cocaine and heroine), to obtain details about the special behaviour of this group. Coomber (1997) acquired information from 80 drug dealers from 14 countries about their approach to adulterate substances, the contamination with other substances to boost the sellable quantity and about the variety of the sold drugs. These findings – important for drug strategies and drug work – were only possible by the use of the internet for drug research.

The aim of the present study, realised 2005, was to determine the appropriateness of the internet to examine the hidden population of recreational drug users and the potential of online drug research. The purpose of exploring the growing population of recreational drug users was to collect information regarding their demographic attributes and their consumption tendency. Furthermore the question should be answered how a trustable information source for them should look like and how they would benefit from it.

Materials and Methods

Sample

Observing the problem of representativeness of online studies and the lack of information regarding the general population of recreational drug users, it is obvious that the description of the population of recreational drug users is a problem. Most studies recruited recreational drug users from clinical or prison settings, so the representativeness suffers (Degenhardt, Carolyn et al. 2007). Collecting data via the World Wide Web anonymously seemed to be the best possibility to acquire the hidden population of recreational drug user. So for the current study data were collected using a specially created website (http://www.xtc-survey.net) for the English-speaking participants and (http://www.xtc-survey.de.vu) for the German-speaking ones. It has to be mentioned that voluntary participation implies a self selection of the sample, but studies comparing internet users with offline testing show similarities with the total population, so the sample can be regarded at least as representative as any other traditional clinical study with recreational drug users. To explore diverse drug cultures with different drug histories, political and legal backgrounds participants the target population were users from North America, Australia, English-speaking and German-speaking Europe. Within ten months collectively 14,193 gave their informed consent by clicking the survey start button on the introduction page. 9,867 unpaid volunteers completed the online questionnaire. The sample included participants who described themselves as current or former ecstasy users; over 99% of them had used ecstasy at least once in their lives. Blank or double filled questionnaires were eliminated. Finally 9,268 questionnaires remained, where significantly more male (72.17%, n=5,625) than female (27.83%, n=2,169) contributed to the survey.

Questionnaire

Two language versions of a specially created questionnaire were programmed as a PHP online survey with a MySQL database behind. The questionnaire took between 10 to 12 minutes to finish. Topics included, besides socio-demographic variables, information regarding drug usage patterns, questions about information sources and the trust in these sources and variables on the subject of online resources for recreational drug users. Socio-demographic variables included amongst others gender, age, marital status, living situation and occupation. Questions regarding sexual orientation were omitted since several studies showed only a moderate elevation of drug use at homo- or bisexual men and women compared to heterosexual men and women (Cochran, Ackerman, Mays & Ross, 2004). The German version was initially analysed using factor analysis, where six relevant factors emerged. The strongest loading factor was factor 1: drug consumption, followed by factor 2: usage of offers, factor 3: acceptance oriented slogans, factor 4: confidence in information sources, factor 5: estimation of offers and factor 6: restriction oriented slogans. The internal consistency for all factors was satisfying between alpha=0.785 and alpha=0.831. Subsequently, the quality criteria of the English version were examined. The “measure of sampling adequacy” (MSA) proved the sample and were satisfying according to Kaiser and Rice (1974) adequacy (MSA= 0.819). The same six factors resulted – as in the German-speaking population – with Cronbach alphas ranging from 0.796 to 0.895. The non-reactive data acquisition included IP addresses for distinct classification and exclusion of double data, technical details and time stamps.

Procedures and Data Collection

An “announcement period” of a few weeks and permanent promotion actions were accomplished. It started with a search engine search for suitable cooperation partners, who should enhance the popularity of the online survey by linking the questionnaire on their website. Using the multiple-site-entry-technique, buttons and banners were provided. Different kinds of cooperation partners were contacted to guarantee a broad spectrum of participants; science-oriented organisations like MAPS (Multidisciplinary Association of Psychedelic Studies) as well as consumer-oriented websites like pillreports.com (a website that provides pill testing results from all over the world). According to potential attendant problems of online research, including multiple submissions of data by the same people and the possibility of mischievous data entry, submitted responses were screened and a number of inclusion respectively exclusion criteria deployed. To detect multiple submissions two techniques were applied: Logged unique identifiers, the IP addresses (in an extra file, because of the guaranteed anonymity) and manual answer-controlling for every data-set, to exclude those participants with variable IP addresses and multiple submissions. By application of the criteria, 4,925 data records were excluded from the initial 14,193 data records; 65.30% of the records were used. There were 4,297 empty data records (information seekers), 268 of the surveys were twofold and 113 specifications about drug consumption were insufficient. 119 data sets were excluded because the persons were exclusively alcohol and nicotine consumers. To control mischievous or fraudulent data entries we used demographic information to screen out the obviously implausible responses (for example subjects alleging to be one year old), an often used technique in web-based research (Rodgers et al., 2003). 128 records had to be excluded for these reasons. To verify results from an earlier online-study of recreational ecstasy users (Stetina et al., 2004) data were compared regarding information sources.

Statistical analysis

The data collected online was directly taken from the database and imported to SPSS. The data was analysed with SPSS 12. The descriptive exploration to analyse the population (German- and English-speaking Europe, North America and Australia) was conducted using explorative data analysis, frequency analysis using contingency tables.

Results

Demographic characteristics of the population

9268 voluntary participants from diverse countries and continents took part in the present study. Survey responses were mainly received from Australia, US, Germany, UK, Canada, Netherlands, Austria, Switzerland, Ireland, as well as from some other European countries. Most participants were from Australia (30.42%, n=2,164) and the US (27.68%, n=1,969). In the German-speaking area, most participants came from Germany (n=1,324). The average age was 22 years (M=22.45, SD=5.91) with a range of 53 years (Min=13, Max=66). The great spectrum of the age distribution of this study showed the enhanced possibilities of the World Wide Web to reach the whole population. The oldest participants were from Great Britain with an average age of nearly 25 years (M=24.64, SD=7.42), second oldest the Dutch with a medium age of 23 (M=23.32, SD=6.31) The youngest group were the users from Austria with a medium age of 21 (M=20.60, SD=4.70). Nearly three quarters of the surveyed population were male (72.17%, n=5,625) and 27.83% (n=2,169) females contributed to the survey. It turned out that the fewest contribution of females were in Great Britain (17.82%; n=477) and the Netherlands (18.10%; n=322). The highest attendance were from Austria (38.49%; n=239), Germany (34.67%; n=1324) and Switzerland (32.46%; n=114). The number of females in the population of recreational drug users declines with the age. There is a highly significant difference looking at the gender distribution in different age groups (χ2 (3, N=7,420) = 134.393, p<0.001). 79.90% (n=6,240) of the participants which made indications about their family status were unmarried. A big part (43.49%, n=3,390) of the participants live with their parents and 20.54% (n=1,601) live with their partner. The largest group of participants which made indications about their occupation group were students (n=2,455, 31.55%), followed by employees (n=1,488, 19.12%), other occupational groups (n=1,223, 15.72%) and workers (n=834, 10.72%). It turned out that 1,507 (19.44%) participants lived in medium-sized towns (20.000 to 100.000 citizens), 1,357 (17.51%) in cities and 1,317 (16.99%) lived in large cities (up to two million inhabitants).

Regional and continental differences

Socio-demographic differences could also be identified. For example 51.5% of the Australian participants lived in million cities, while only 16.28% of the German-speaking European did. Also regional varieties of the consumption and the combination of substances could be indicated. In German-speaking Europe cocaine and nicotine were the most commonly used drugs. The combination of ecstasy and speed was most commonly used in Australia (M=3.01; SD=1.22) and almost never in North America (M=1.53; SD=0.97), whereas the combination with psychedelic mushrooms was rare everywhere. In English-Speaking Europe the consumption of ecstasy and alcohol were widespread (M=3.62; SD=1.32) and in North America unusual (M=2.23; SD=1.35).

The average age for the first consumption varied between countries. In German-speaking Europe the average age of the first consumption was 18 years (M=17.88; SD=3.65), in North America (M=19.34; SD=5.16) and in Australia (M=19.50; SD=4,.60) it was above 19 years and in English-speaking Europe (M=20.15; SD=5.97) it was above 20 years. In English-speaking Europe the highest duration of consumption was between two to four years (M=3.30;SD=1.55), similar to Australia (M=2.94; SD=1.49), North America (M=2.89; SD=1.53) and German-speaking Europe (M=2.65; SD=1.49) where the period of consumption lies between two to three years. Also the different ratings of slogans from various prevention measures were analysed. It could be established that “accept orientated slogans” like “Know your body. Know your mind. Know your substance. Know your source.” were more attractive for North American participants and were less attractive for German-speaking European. Offerings from the internet were more often used by North Americans (even repeatedly per month), followed by Australian, English-speaking and German-speaking European. Drug analysis, virtual drug counseling and discussion forums were used more often by Australian and North American people. It could be shown that flyers were used more often in German-speaking Europe than in all other areas.

Drug usage

Most of the participants (98.81%, n=9,158) had used ecstasy at least once in their lives, whereas 6786 (74,62%) declared to be recreational drug users and 2308 (25.38%) were former ecstasy users. The average age of the first ecstasy consumption was 19 years (M= 19.00; SD= 4.70) and the average duration of drug usage was four years (M=4.10; SD= 0.93). The mean quantity of ecstasy consumption per weekend was three consumption chunks. The range lies between a quarter unit to 40 units (!), these participants were called “Binge-Users”. More female (25.54%, n= 544) than male recreational drug users (21.08%, n=1,168) consumed ecstasy every weekend. Furthermore it could be shown, that younger participants consumed more ecstasy, than the older ones.

Besides ecstasy other drugs were also used. Almost all (99.55%, n=8,859) participants additionally consumed legal substances like nicotine (78.60%, n=7,182) and alcohol (95.83%, n=8,683). Besides the use of ecstasy (98.81%, n=9,145), other illegal drugs such as cannabis (91.31%, n=8,196), amphetamine/methamphetamine (69.67%, n=6,322), cocaine (58.52%, n=5,260), mushrooms (51.45%, n=4,586), LSD (41.41%, n=3,701) and other drugs like ketamine, GHB, TMA-2, 4-MTA and PMA were listed by the participating users. 94.62% (n= 8769) of participants practiced a polyvalent consumption of ecstasy and the above listed substances. Consumption reportedly took place at parties and rave events (72.88%, n= 6847), at friends and acquaintances (68.16%, n= 2207) as well as in clubs and discos (64.09%, n= 5940).

Information sources

Recreational drug users refer to various information sources for drug-related information. One of the most used information sources is the internet (74.02%, n=6,860), followed by friends and acquaintances (71.32%, n=6,610), their dealer (38.23%, n=3,543), radio and television (17.16%, n=1,590), scene magazines (15.72%, n=1,457) and daily newspapers (15.40%, n=1,472). More than 7.10% of the participants named further sources of information about “drugs” which they make use of. They use, among others, scientific studies and literature (n=192), personal experience (n=70) and special offers and websites on the internet (n=257) such as http://www.erowid.org or http://ww.pillreports.com. To show the relevance of the results, data from another online study by the authors (Stetina et al., 2004) are included in table 1.

Table 1: Drug-related information sources

 n Frequencies
 Stetina et al. 2004present studyStetina et al. 2004present study
internet1220686072.23 %74.02 %
friends1204661071.24 %71.32 %
dealer813354348.08 %38.23 %
radio/TV763159045.12 %17.16 %
scene magazines750145744.38 %15.72 %
daily papers749147244.33 %15.40 %
drug advice centres 21196712.49 %10.43 %
scene initiatives1621024 9.60 %11.05 %
(public) health authorities168640.93 % 9.32 %
school/teacher13502 0.84 % 5.42 %

In addition to the massive use of the internet as a source of drug-related information, the trust in an information source is another relevant topic. Using a five-point scale reaching from absolute trust, a lot of trust, moderate and marginal trust to no trust at all, the participants were asked to rate their drug-related information sources. Looking at the sources with absolute trust friends are the most trustworthy information source. 18.38% of the participants absolutely trust their friends and 33.22% trust their friends a lot. On the second position the relevance of drug advice centres becomes apparent as 14.67% of the participants absolutely trust the information from drug information centres and 26.10% trust them a lot. The internet seems to be nearly as trustworthy as drug information centres for the participants of the present study: 14.52% absolutely trust the internet and a tremendous 42.93% trust the drug-related online information a lot. Looking at the extent of trust on a three-point scale to compare it with other studies, the position of the internet is top ranking with 56.45% in front of friends with 51.60% (see table 2).

Table 2: Trust in information sources

 absolute trust / a lotmoderate trustno trust at all / marginally
internet56.45 %32.00 %11.55 %
friends/acquaintances51.60 %32.77 %15.63 %
drug advice centres40.77 %27.39 %31.84 %
health civil service24.92 %29.50 %45.58 %
drug-scene-initiatives24.15 %33.90 %41.95 %
magazines21.24 %36.44 %42.32 %
dealer18.19 %28.79 %53.02 %
radio/TV9.31 %25.81 %64.89 %
daily newspaper7.95 %22.95 %69.10 %
school/teachers9.02 %22.02 %68.96 %

Discussion and Conclusion

It could be shown that the application of the World Wide Web has the potential to reach the hidden population of recreational drug users. In addition to inconspicuous populations, the implementation of online-conducted studies could be an opportunity for the exploration of rare phenomena. Beside the incredibly large quantity of participants, the World Wide Web also offers enormous specificity. It offers, based on its anonymity, the chance to approach other people and to recruit hidden populations for numerous areas of research, like recreational drug users (O`Connell & Bou-Matar, 2007), HIV-infected people (Nguyen et al., 2008) or homosexuals (Evans et al., 2007). Furthermore, the internet provides a tremendous potential for prevention measures and health promotion. The online information sources are very complex.

The present study shows that recreational drug users use various information sources. The most used was the internet, followed by friends and acquaintances, dealers, radio and television, scene magazines and daily newspapers. Other information sources were medical and pharmacology books, peer-reviewed studies and research papers. To show the relevance of the results, data from an earlier study of the authors was included in table 1, to see the clear trend regarding the relevance of the internet as the primary drug-related information source. Although there are big differences regarding the sample size, both studies show the same tendency toward the internet as top information source for recreational drug users. Compared with an older study by Schroers and Schneider, who surveyed 385 clubbers in 1998, attending an event, it is obvious that the internet as information source is a relatively new development. The internet was not even mentioned as a possible drug-related source of information. Above all, friends are the leading information source with 85.71%. The second most named information source is magazines (66.02%) followed by radio and TV (47.10%), scene initiatives (40.15%), dealers (20.08%) and other information sources. Compared with another recent on-site study with 58 ecstasy users (Wundsam, 2006) the changes in the last years are noticeable. Although friends are the top information source (89.66%) they are followed directly by the internet with 67.24%. All other drug-related information sources are used far less. Radio and TV take the third place (29.31%), daily papers (27.59%) on the fourth followed by dealers (25.86%) and the other information sources.

Interestingly, the trust in these information sources was quite different. Information which was received from friends, well known people and counselling centres was assessed more credible than information from the internet. Also, the intake of drugs basically takes place at friends and well known people, at parties and rave events and in clubs and discos. In earlier research (Schroers & Schneider, 1998), with acquisition of participants directly in the party setting, friends were rated the most trustworthy information source with 55.93% followed by scene initiatives (54.80%), flyers (48.87%), drug advice centres (43.79%), health civil services (26.99%) and others. Looking at a recent small study (Wundsam, 2006) with 58 ecstasy users, which was also conducted at an event, the evidence of the internet is clear. Although drug information centres are most trustworthy for the participants with 69.39% of them trusting absolutely or a lot, the ranking is on the whole not very different from the present results. 53.45% trust friends and acquaintances absolutely or a lot and the internet is in the third place with 44.90% absolute or lot of trust from the participants.

It was shown that the surveyed population differs from the on-site population mainly regarding age. The age in the present study ranged from 13 years to 66 years, and especially the group of older recreational drug users can not be reached using traditional designs. A broader range compared with the small on-site study with participants from 18 years to 33 years old. About 5% of the surveyed users were 30+ years old. In the present study nearly 2000 users (about 11%) were 30+ years old. This consumer group is usually even more inconspicuous in society and those people are not the usual clubbers. Particularly this age group can be perfectly reached online. It could be that this sample of recreational drug users online is “more representative” for the group of recreational drug users. Because of the lack of knowledge regarding the concurrent general population this question will remain unclear.

In online surveys there are situational characteristics concerning the state of the subjects, which cannot be controlled. Whereas the actual concentration of various substances can be determined by urine samples at face to face interviews, this is not possible for online surveys. In return, online surveys provide the opportunity to answer in a much more anonymous way.

Altogether, the advantages of the internet as a medium for data ascertainment outweigh the disadvantages for the specific population of recreational drug users. As mentioned above, the target group of recreational drug users is inconspicuous in society und therefore it is a population which is rather difficult to access. The value of online-surveys as a method of accessing this population was already mentioned (e.g. Nicholson et al., 1998; Reneau et al., 2000). This target group, considering the rather youthful age and the higher level of education, belongs to a population group which uses the internet to a very high extent. Recreational drug users are highly interested in the substances they use and have a high “involvement”. The internet is the most used source of information for consumers. It is assumed, that there is a certain readiness to answer a “longer” questionnaire and thus the drop-out rate is moderate. The prospect of an adequately large sample to describe the population is higher by means of an online survey than by a paper-pencil-version of the same questionnaire. The internet provides the opportunity to collect a large amount of data, which was open only for government agencies and big organisations a few years ago. Furthermore, the investigation of an adequate large sample is much more economical by means of the internet in comparison to other methods (Couper, 2000; Tuten, Urban & Bosnjak, 2002). Thereby, also cross-national and cross-continental research is possible in a reasonable time-frame.

Finally, the well-known explorative online-survey by Coomber (1997) shall be mentioned again. This first example for the access to a population which is invisible and inaccessible by conventional methods shows the most important advantages which online surveys have to offer.

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Correspondence to:
Birgit U. Stetina
Institut für Klinische, Biologische und Differentielle Psychologie
Fakultät für Psychologie
Universität Wien
Liebiggasse 5, 1010 Wien
T: +43 1 4277 47971
F: +43 1 4277 47979
e-mail: birgit.stetina(at)univie.ac.at