CHANGING COCAINE SMOKING RITUALS IN THE
ROTTERDAM HEROIN USING POPULATION

Contents
Introduction
Heroin Self-Administration Rituals and Cocaine Preference
Preparing Cocaine-Hydrochloride for Self-Administration
The Emergence of Gekookte Coke
The Distribution of Gekookte Coke
Motivations for Using Gekookte Coke
Discussion
Conclusions
References

Introduction

In recent years the use of cocaine has become of interest to both researchers and policy makers in Europe. However, there have been few studies that document European cocaine use patterns, circumstances and consequences. In several pilot studies conducted in Rotterdam, cocaine use patterns, circumstances and consequences have been described in the population of heroin users. (1 2) The Rotterdam cocaine studies were extended into a European context with compatible pilots conducted in Munich and Rome. Across these different European cities, relatively common and distinctive cocaine using groups and milieus could be specified. It was determined that cocaine use was prevalent across a wide range of social groups including actors and artists, blue collar workers, students, unemployed, white collar, pimps and prostitutes and people with restaurant, bar and cafe occupations. (3) In Amsterdam during the same time period, Peter Cohen completed an extensive study of 160 persons with an inclusion criterion of a minimum of twenty-five lifetime instances of cocaine use and an exclusion criterion of deviant subcultural origin (junkies, criminals, prostitutes). The results of the Amsterdam study were able to be compared with data from the North American cities of Miami (4 5) and Toronto (6). In the Amsterdam sample, the great majority (70.3%) had a lifetime prevalence of cocaine smoking and a sizable minority of free basing (18.1%). However, in terms of current prevalence, the large majority of the sample (73.6%) always used intranasally. Only a tiny percentage of the sample (0.6%) had a current prevalence where cocaine was always smoked. For those who had some smoking and basing lifetime experience, half the sample (50.8%) did so rarely for smoking and a much smaller percentage (16.9%) rarely for basing. The Amsterdam study revealed, at least for the non-deviant subpopulation of cocaine users, a rare current prevalence of cocaine smoking or basing patterns. (7)

Despite the popular opinion that Europe was somehow generally behind the United States in the incidence of cocaine use patterns, the Dutch cocaine studies suggested that a number of American patterns could be observed and that they have been in existence for sometime. In both heroin user and non-heroin user populations, cocaine smoking has existed as a common form of self-administration. Historically, cocaine smoking in the form of free basing had entered the United States in the late 1970s among higher dealer circles. (8 9 10 11) By the 1980s, changes in the international cocaine market stimulated the release of a product called crack which was ready-made pieces of smokable cocaine-base that was marketed to a new consumer group, the young underclass. (12 13) James Inciardi documents these changes as follows:

The rediscovery of crack during the early 1980s seemed to occur simultaneously on the East and West Coasts. As a result of the Colombian government's attempt to reduce the amount of illicit cocaine production within its borders, it apparently, at least for a time, successfully restricted the amount of ether available for transforming coca paste into cocaine- hydrochloride. The result was the diversion of coca paste from Colombia, through Central America and the caribbean, into South Florida for conversion into cocaine. Spillage from shipments through the Caribbean corridor acquainted local island populations with coca paste smoking, which developed the forerunner of crack-cocaine in 1980. Known as baking-soda base, base-rock, gravel, and roxanne, the prototype was a smokable product composed of coca paste, baking soda, water, and rum (10).

As Inciardi's account suggests, the smoking of cocaine involves a highly complex political economy which results in the production of a great variety of cocaine smoking products that appear and reappear at various times and places. In the Netherlands, the incidence of cocaine smoking has been documented at about the same time as in the United States (14)

On the demand side, the form of cocaine smoking is related to the interaction between user preferences, price, purity and perceived availability. This interaction results in the formalization of distinctive sequences and meanings associated with the consumption of a drug. These stylized interaction forms have been referred to as drug-administration rituals. The concept of ritual has been a mainstay in the ethnographic literature on drug use. Michael Agar has defined the conditions for ritual events: "For an event to be a ritual event it must prescribe a sequence of psychomotor acts and this prescribed psychomotor sequence must be invested with a special meaning for the person performing that sequence". (15) As Agar has argued, different ritual self-administration of the same drug may involve very different sequences of psychomotor behavior and quite different meanings for the user. In this regard Griffith Edwards statement about heroin may be said to apply to cocaine, insofar as the smoking provides a different effect then injecting. (16) Different from heroin, however, is that for cocaine the smoking effect may be comparable to or even more rapid and intense than injecting. (17 18 19) Moreover, even within the smoking route of self-administration of cocaine the effects may differ. Smoking from a (chamber) pipe provides a more intense effect than chasing.

In this chapter the emergence of a new Dutch cocaine smoking product, cooked coke (gekookte coke) is discussed within the broader context of older cocaine self-administration smoking rituals among heroin users. The prevalence, preferences and self-administration rituals of cocaine use are documented in a series of Rotterdam field studies. Special emphasis is placed upon the emergence of cooked coke highlighting its origins, sales and user motivations. The appearance of cooked coke is compared as an emergent social phenomenon with the appearance of crack cocaine in the Americas. It is suggested that political as well as economic conditions may account for both the appearance and spread of this specific cocaine smoking product.

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Heroin Self-Administration Rituals and Cocaine Preference

In the Netherlands, two predominant rituals can be distinguished in cocaine self-administration by heroin users --injecting and smoking. These cocaine rituals correspond to the predominant patterns of heroin self-administration. The most common mode of smoking cocaine (and heroin) is called "chinesing" (chasing the dragon or chasing) in The Netherlands. When chasing, some of the drug is put on an oblong piece of tin foil and heated from underneath. The drug melts, vaporizes and runs along the foil. The vapors are inhaled through a tube which is held in the mouth. With this tube the running and vaporizing liquid is carefully followed (chased) while inhaling. Depending upon the amount of cocaine-base placed on the foil, the chasing involves five to ten runs over the foil with a corresponding number of inhalations. In contrast, the same amount of cocaine-base administered in a free base pipe may only take one or two inhalations producing a much more intense impact effect. In both the observational study and the Central Station survey the preference for smoking rituals among Dutch heroin users is confirmed; only the minority of those people observed (23%) have injecting as their main self-administration ritual while the sizable majority (77%) seem to prefer the smoking form of self-administration. In the survey only 23% injected heroin and 28% injected cocaine. It is clear from both the field observational data and the survey data that cocaine has become increasingly important to Dutch heroin users. The prevalence of cocaine use in this population is rising to alarming levels.

Figure 15.1

Figure 15.1 presents the drugs of first and second choice in the Central Station survey. While heroin is the drug of first choice for 34 respondents cocaine (and methadone) are drugs of first choice for a sizable proportion of the sample (8 for cocaine; 6 for methadone). Looking at drugs of second choice, cocaine is clearly the most prevalent drug of second choice (20 respondents). Compared to the other drug classes (methadone, alcohol, pills and others) cocaine and heroin are in a class of themselves--both are the preferred drugs in this population. The data on the research subjects in the observational study (which was collected about a year later) show that 96% of the heroin users is combining their use of heroin with cocaine (N = 105). In comparing the validity of these findings, 1988 data from the Rotterdam registration system of heroin users in methadone treatment report a prevalence of 72% (N = 1797) cocaine use, not as high as our community users sample but still almost three-quarters of this treatment sample. (20)

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Preparing Cocaine-Hydrochloride for Self-Administration

The heroin users observed in this study either speedball (mix) the cocaine with heroin or turn- take them (first cocaine followed by heroin). Additionally, all the dealing addresses that were studied sold both cocaine and heroin to their customers. As mentioned above, the way cocaine is ingested parallels the form used to self-administer heroin; injecting drug users (IDUs) generally inject cocaine-hydrochloride and heroin smokers normally chase or base cocaine- base. In The Netherlands cocaine has been generally marketed in the hydrochloride form. IDUs simply dissolve the drug in water before injecting. Smokers convert the cocaine- hydrochloride into cocaine-base themselves. They chemically remove the Hcl group by use of ammonia or baking salt (bicarbonate) before they ingest the drug via their preferred route. Chapter five presented this process in detail.

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The Emergence of Gekookte Coke

Thus, cocaine smokers have to perform a rather laborious and time consuming routine to prepare the cocaine-hydrochloride. This tedious task needs specific tools and chemicals as well as a significant amount of time. This preparation routine can hardly be performed properly outside of a house or other similarly quiet place. In many Dutch cities retail heroin and cocaine dealing inside of houses which does not cause any nuisance to the neighborhood is often tolerated. In Rotterdam, most users buy and often use their drugs at these dealing places called addresses. At most addresses the dealer, who is almost always also a drug user, the opportunity is offered the customers to use the purchased drugs on the premises although generally IDUs are excluded from this privilege. Routinely spoons, ammonia, tinfoil, tissue, toilet paper and water are supplied by the dealer.

Not all drug users have access to these places all of the time. Temporarily, some users are denied entry if they do not buy or are known to be in (enduring) financial need. Other users are denied access more permanently. Usually this is because their behavior and reputation does not conform to subcultural expectations. Among the permanently barred users, the most marginalized polydrug users can be found. Together with people that come to socialize, buy methadone or prescription drugs, these marginalized users drift toward the Central Station zone where they are both tolerated and constitute the majority of drug users. In this environment among these marginalized addicts, the emergence of a form of cocaine-base called gekookte coke (cooked cocaine) was first documented by the field research team in February, 1990. Intensive inquiry with users already recruited in the study revealed that cooked cocaine had already been available for quite some time at the Central Station. One informant maintained that it has been available for more than two years; another spoke of a half-year. Interestingly, however, when asked whether they knew where to buy crack, no one could say they knew where to find it. When asked for cooked cocaine, everybody immediately understood and said it was for sale at the Central Station.

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The Distribution of Gekookte Coke

Cooked cocaine is sold at the Central Station mainly by Surinamese and Moroccan drug users. They do so to support their own drug habit. Other drug users were often observed bringing customers in exchange for a commission. Cooked cocaine is one among the many other drug products (heroin, cocaine-hydrochloride, methadone and prescription drugs) they offer. All of their selling is done in very small units. Normally, these street dealers buy a gram of cocaine- hydrochloride and cook it with ammonia or sodium bicarbonate. Additional refining with ether is not performed. The resulting lump of cocaine-base is crushed, powdered and divided into small amounts, usually just enough for one smoke. These portions are packed in a small piece of plastic wrapper, folded into the form of a drop and sealed by melting the plastic. They are called een balletje (a little ball) and are sold for about ¦10.- (approximately $6.- or £3.-) each. Because of factors relating to both the packing of the drug and the rushed atmosphere of a street drug sale, the consumer has much less control over the purchased product. Thus, heroin or cocaine bought at the Central Station are seen as the worst buys in the city. For the purpose of the analysis of content some samples of cooked cocaine were collected. The following fieldnote documents the interaction:

It is Thursday night, 22.50 hour. I am walking through the Central Station hall, which is rather quiet. I decide to take the stairs down to the subway station. Halfway down the stairs, at the entrance of the bicycle storage department two Moroccan men in their early twenties and a middle aged Dutch woman are arguing loudly. They are not rushing bypassers hurrying for their train. Walking down the next part of the stairs, I am crossed by a Creole Surinamese man. "Coke?", he whispers. I smile and walk on. Downstairs, apart from a group of four users, the hall is empty. As I walk by I hear a voice whisper "Bruin, ... Coke?". At the end of the hall I slow my pace, observe the group for some seconds and walk their way again. The same voice speaks to me again. It is a blonde Dutch man in his late thirties with a very thin face. He asks if I want to buy coke. "I could see you are a user, although you look good", he flatters me. He has an unknown accent. I ask for gekookte coke (cooked cocaine). Then everything goes very fast. He starts walking and we take the stairs for the square in front of the station. In the entrance of the station hall he approaches a Hindustani Surinamese man of about 35 years and tells him I am a potential customer. For not one moment is there any mistrust and the dealer is willing to sell. The blonde man asks how much money I want to spend. He reports to the dealer that I want to buy for 25 guilders. Next the dealer hands me two tiny drop alike pieces of plastic, containing white powder. The blonde guy assures me the merchandise is of good quality. "If you like you can smoke in the phone booth", he says pointing at the one we are standing next to, "If you're not satisfied, you can come back to me." The dealer says that he regularly smokes in the phone booth so that is not a problem. As I do not have the exact sum and the dealer cannot change, he settles for 24 guilders. When I leave the blonde guy starts to negotiate about his commission.

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Motivations for Using Gekookte Coke

All of our informants stated that cooked cocaine is sold at the Central Station for very pragmatic reasons:

"You don't have to prepare it."
"It is ready for smoking."
"It's a gain of time."
"It is not so conspicuous when you don't have to prepare before smoking."
"You don't have to search for a place to cook the stuff anymore."
"You don't need a spoon and ammonia."

The situation at the Central Station zone upon which these reasons are grounded is characterized by specific ecological conditions which have made the adoption of cooked cocaine functional to this group of drug users. There is neither the time nor space at the Central Station zone to cook cocaine-hydrochloride. Especially in the daytime, the zone is crowded by high concentrations of passing travellers. During these hours, the resident group of drug users and other marginals are closely watched by the police. Often they are summoned to move along. The hall of the station is easy to survey and in the past measures have been taken to limit the use of drugs at the station. Thus, there is an incentive to have a smoking product that can be smoked as quickly as possible in any available nook or nitche, for example a telephone booth. Included in the convenience advantages of cooked cocaine are that the user is freed from the necessity to carry around the paraphernalia and chemicals for the preparation of smokable cocaine.

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Discussion

In light of the international uproar about crack cocaine precipitated by the experiences of the Americas, the appearance of cooked cocaine in the Netherlands, though sporadic and restricted to a relatively small subpopulation of drug users, is nonetheless worthy of attention. Cooked cocaine and crack are basically similar products. Both are forms of cocaine-base processed from cocaine-hydrochloride containing various impurities and adulterants that are added during production and trafficking. There are however some apparent differences. Cooked cocaine is prepared in quantities of a gram or less by users that sell the substance to their peers. On the other hand, crack generally is prepared in larger quantities in a kind of cottage industry setting. Williams described a teenage drug ring involved in crack sales. The basic recipe of this group's mixer started with 125 grams of cocaine-hydrochloride. Obviously, one essential difference between cooked cocaine and crack is the scale of production. (12)

Another obvious difference between cooked cocaine and crack is the target group and population of users. In the United States crack has been marketed to new user groups that previously were not involved in heroin or cocaine use. In Rotterdam, the sale of cooked cocaine is limited to a small proportion of the existing heroin using population confined to an area where self-preparation of cocaine-base is hardly feasible. The majority of heroin users prefer to buy and self-prepare cocaine-hydrochloride at house addresses. The use of cooked cocaine has been restricted to the most marginalized polydrug users in the heroin using population. These users are the most vulnerable to the turbulence in the local drug market and cannot find a stable address or living arrangement in order to self-produce their own smokable cocaine. It is also notable that this group's social marginality seems to be correlated in part to ethnic group membership with Moroccan and Surinamese drug users being the most likely to sell and use cooked cocaine.

While the current prevalence of cooked cocaine in Rotterdam seems well contained, there do exist certain conditions that could lead to an expansion of this market. In contrast with many neighboring countries and the United States, in the Netherlands only a minority of heroine/cocaine users have been reported to inject. Most Dutch drug users smoke their drugs. (21 22 23) This suggests that in the heroin-using population in the Netherlands a ready market potential for crack cocaine --a cheap cocaine product especially designed for adapted hard drug smokers-- is already in existence. However, according to the Dutch Ministry of Health, crack use is not prevalent in the Netherlands (24). The research results presented here suggests that the reality is more complicated. Congruent with a number of other independent studies, a large proportion of Dutch heroin/cocaine users are currently preferring the smoking route of self-administration. The established ritual of chinesing or chasing of heroin has been applied to a new situation of the increased availability of cocaine on the heroin market. Basing of cocaine, a different way of smoking the same cocaine product, is also prevalent. And now the most recent development has been the appearance of cooked cocaine as a new packaged product on specific street drug markets. All of these developments can be contrasted with the non-deviant cocaine using population where nasal inhalation seems the most stable and prevalent route of self-administration and cocaine smoking in any form is rare. (7)

The development of a stable smoking ritual in the Netherlands provides yet another example of the importance of economic factors on the determination of forms of drug self- administration. In this regard, several recent studies conducted in both Britain and the United States have found that economic pressure is perhaps the most important factor in the initiation of injection as the stable and prevalent self-administration ritual. (25 26 27 28) Because this specific economic pressure is minimalized in The Netherlands, large proportions of Dutch drug users do not experience the necessity to initiate and maintain injection as do their British and American counterparts. An additional economic subfactor peculiar to the Netherlands is recognition of organized drug traffickers of the preference for smoking heroin. Thus, in the second half of the Seventies, Turkish and later Pakistan smoking heroin was introduced in large quantities. This marketing strategy by the traffickers further helped to stabilize the smoking pattern and preference. Analytically, this economic factor is a rather complex system in itself, consisting of a dynamic equilibrium of both demand and supply-side subfactors.

The initiation, maintenance and emergence of the cocaine smoking patterns cannot be reduced to a single factorial explanation based solely on economic forces. Psychological factors also have a role to play. Thus, a current psychological determinant may be the fear of contracting AIDS through the use of unsterile needles. (29) Associated with this psychological factor are specific subcultural factors, e.g. The existence of certain needle taboos in specific ethnic groups. And the ritual form itself may produce a specific sociocultural reward for the participant including a sense of solidarity, meaning and emotion. (30) In the sociocultural context of an already dominant heroin smoking ritual, the economic factor of the increased availability of cocaine came into play in the heroin scene during the first half of the Eighties. (2) The preparation of cocaine for smoking became an important part of the self-administration ritual and added a new dimension of meaning to the drug subculture. The preparation of cocaine- base is almost as an important part of the ritual as the actual act of smoking and its impact effect. Users perform the preparation sequence in a stylized manner with much precision and dedication. Preparation is an important act in which they do not want to be disturbed. Although idiosyncratic variations on this routine can be observed, the behavioral sequence is highly predictable and subject to various levels of ritualization. (15 31 32)

Along with the economic, psychological and sociocultural factors a significant political factor can be distinguished. The self-preparation of cocaine is preferred because this act allows the user to increase the control the user has over the product vis-a-vis the dealer. Yet, this routine can hardly be performed outside a building, frequently a dealing address controlled by an equilibrium of dealer and police forces. It is almost impossible to prepare smokable cocaine in crowded surroundings such as at the Central Station and other street areas where high levels of police repressive activity are directed. Under these political conditions, preprocessed, cooked cocaine has become available. The local political conditions have provided an exogenous stimulus to the economic equilibrium. On the supply side politics has changed the market and unintentionally encouraged entrepreneurial ventures in cooked cocaine. On the demand side cooked cocaine represents an adaptation to the exogenous political stimulus that satisfies the existing demand for smokable cocaine.

In addition to these local micro political subfactors, there may be other, more macro level political factors which have determined the emergence of both cooked cocaine and crack. Inciardi has contended that drug war interdiction policies could well be a factor in itself toward the creation of a higher demand for crack.

Even if the federal War on Drugs is at all successful in the interdiction of cocaine coming into the United States, the use of crack will still persist. In fact, a successful war might serve to make crack even more desirable. Should interdiction drive the price of cocaine up to $300.- or even $400.- a gram, a few hits of crack could still be had for under $100.-.(10)

Together with sensationalist mass media coverage definition and governmental high-key prevention campaigns (33), the emergence of crack may indicate how a new drug fad can be inadvertedly created that reinforces the natural economic dynamics of supply and demand. In The Netherlands, despite official national government policy, local efforts that have a more warlike profile may be functioning to produce pockets of cooked cocaine use. Currently, the sale of cooked cocaine at the Central Station in Rotterdam cannot be said to signify a trend of wider significance. Nevertheless, there has been an increased tendency of police raids aimed at closing down dealing addresses in the west of Rotterdam. The result has been that many users who previously have had a stable address have been disconnected from their regular sources of supply. This turbulence has had unanticipated consequences. AIDS outreach workers who operate in that part of the city report that they have lost contact with a number of their clients only to find them again in the Central Station zone. (34)

Somewhat associated with this local tendency has been, as in the United States, a decreasing availability and quality of cocaine. A Dutch heroin user echoes the sense of Inciardi's argument on the consequences of vigorous interdiction policies: "You know, you have to search well to get some good coke and when you find some, they tell you the price has gone up because good coke is hard to find, they say." Interestingly, this change of policy has not effected the heroin market. The price of heroin has remained stable at about ¦100.- a gram (approximately $60.- or £30.-) while the price of a gram of cocaine has risen from that amount to about 140 guilders. If this tendency continues, a new Dutch situation may be ushered in where the marketing of commercially innovative, cottage industrial cocaine-base products such as crack will both increase the profit margin and meet the demands of users who are forced to adapt their drug-taking rituals to the changing conditions of a decreasing number of house addresses and an increasing time spent on the streets.

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Conclusions

In conclusion, the local high-profile police experiments will be judged by their results given the Dutch commitment to a pragmatic drug policy. In the Netherlands, cooked cocaine will probably not spread in the heroin using population if the current preferences of users toward self-preparation of cocaine-base is reinforced. In a situation in which the majority of smoking users can prepare their cocaine-base without fear of being harassed, an effective protective factor (35) against the spread of a cooked cocaine epidemic in this population can be said to function. However, if local policy changes the conditions of, not only, the availability of cocaine, but also of the time and space allocations of drug users, this may result in a supply shift from cocaine-hydrochloride to cocaine-base at the level of middle market distribution. As a socio-economic phenomenon, Dutch cooked cocaine would be transformed into American crack. The risk of spillage into populations of non-deviant users of cocaine-hydrochloride which now purchase their cocaine through retail sellers outside the heroin scene may well increase through a mechanism of shortages. The risk of a crack epidemic could then become eminent. It might not be too much to say, that the current difference between cooked cocaine and crack is largely the result of drug control policy determinants. Cooked cocaine is the exception to the rule of a normalization policy that aims at socially integrating drugs and their settings into nitches of conventional society, while crack is the explosive by-product of a policy aimed at eliminating cocaine and its settings of use in the quest for a drug-free society.

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References

  1. Kaplan CD, Janse HJ, Thuyns H: Heroin smoking in the Netherlands, In: Drug abuse trends and research issues, Community Epidemiology Work Group Proceedings. Rockville: NIDA; 1986: III-35-45.
  2. Kaplan CD, Tappin CP, Thuyns H: Cocaine and sociocultural groups in the Netherlands. In: Kozel NJ (ed.): Epidemiology of drug abuse: Research, clinical and social perspectives. Rockville: NIDA; 1985: IV 5- 16.
  3. Avico V, Kaplan CD, Korczak D, Meter K van: Cocaine epidemiology in three European Community Cities: A pilot study using snowball sampling. Rotterdam: Addiction Research Institute, Erasmus University, 1988.
  4. Chitwood D: Patterns and consequences of cocaine use. in: Kozel N, Adams E (eds.): Cocaine use in America: Epidemiologic and clinical perspectives. Rockville: NIDA, 1985.
  5. Morningstar P, Chitwood D: The patterns of cocaine use -An interdisciplinary study-, Final report No. RO1 DA03106 submitted to the National Institute on Drug Abuse. Rockville: NIDA, 1983.
  6. Erickson P, Adlaf E, Murray G, Smart G: The steel drug. Cocaine in perspective. Toronto: Lexington Books, 1987.
  7. Cohen P: Cocaine use in Amsterdam in non-deviant subcultures. Amsterdam: University of Amsterdam, 1989.
  8. Siegel RK: Cocaine smoking. Journal of Psychoactive drugs 1982; 14: 271-359.
  9. Adler P: Wheeling and dealing. An ethnography of an upper-level drug dealing and smuggling community. New York: Columbia University Press, 1985.
  10. Inciardi JA: Beyond cocaine: Basuco, crack, and other cocaine products. Contemporary Drug Problems 1987; 14: 461-492.
  11. Inciardi JA: The war on drugs: Heroin, cocaine, crime and public policy. Palo Alto: Mayfield, 1986.
  12. Williams T: The Cocaine Kids; The inside story of a teenage drug ring. New York: Addison-Wesley, 1989.
  13. Hall JN: Hurricane Crack. Street Pharmacologist 1986; 10(9): 1-2.
  14. Boetje H: Free-basen, een nieuwe methode van cocainegebruik. Nederlands Tijdschrift voor Geneeskunde, 1984; 128(47): 7737-7738.
  15. Agar MH: Into that whole ritual thing: Ritualistic drug use among urban American heroin addicts. In: Du Toit BM (ed.): Drugs, rituals and altered states of consciousness. Rotterdam: Balkema, 1977: 137-148.
  16. Edwards G, Arif A, Jaffe J: Drug use & Misuse: Cultural Perspectives. London: Croom Helm, 1983.
  17. Gawin FH, Kleber HD: Abstinence symptomatology and psychiatric diagnosis among cocaine abusers. Archives of general psychiatry. 1986; 43: 107-113.
  18. Wallace BC: Treating crack cocaine dependence: The critical role of relapse prevention. Journal of Psychoactive Drugs 1990; 22(2): 149-158.
  19. Washton AM, Stone-Washton N: Abstinence and relapse in outpatient cocaine addicts. Journal of Psychoactive Drugs 1990; 22(2): 135-147.
  20. Toet J, Ven APM van de: Het RODIS uit de steigers. Resultaten 1988 Rotterdam, Rapport 65. Rotterdam: GGD afdeling Epidemiologie, 1989.
  21. Buning EC, Coutinho RA, Brussel GHA van, Santen GW van, Zadelhoff AW van: Preventing AIDS in drug addicts in Amsterdam. Lancet 1986; ii:1435.
  22. Korf DJ, Hogenhout HPH: Zoden aan de dijk: Heroinegebruikers en hun ervaringen met en waardering van de Amsterdamse drughulpverlening. Amsterdam: Instituut voor Sociale Geografie, Universiteit van Amsterdam, 1990.
  23. Korf DJ, Aalderen H van, Hogenhout HPH, Sandwijk JP: Gooise Geneugten: Legaal en illegaal drugsgebruik (in de regio). Amsterdam: SPCP Amsterdam, 1990.
  24. Engelsman EL: Dutch policy on the management of drug related problems. British Journal of Addiction 1989; 84: 211-218.
  25. Casriel C, Rockwell R, Stepherson B: Heroin sniffers: between two worlds. Journal of Psychoactive Drugs 1988; 20(4): 37-40.
  26. Parker H, Bakx K & Newcombe R: Living with heroin: The impact of a drugs 'epidemic' on an English Community. Philadelphia: Open University Press, Milton Keynes, 1988.
  27. Burt J & Stimson GV: Report of in-depth survey of intravenous drug use in Brighton. London: Monitoring Research Group, 1988.
  28. Power RM: The influence of AIDS upon patterns of intravenous Use- Syringe and Needle Sharing- among illicit drug users in Britain. In: Battjes RJ, Pickins RW (eds): Needle sharing among intravenous drug abusers: National and international perspectives. Rockville: NIDA, 1988: 75-88.
  29. Ghodse AH, Tregenza G, Li M: Effect of fear of AIDS on sharing of injection equipment among drug abusers. British Medical Journal 1987; 295: 698-699.
  30. Collins R: Towards a neo-Meadian sociology of mind. Symbolic Interaction 1989; 12(1): 1-32.
  31. Carter WE: The Aymara, and the role of alcohol in human society. In: Du Toit BM (ed.): Drugs, rituals and altered states of consciousness. Rotterdam: Balkema, 1977: 101-110.
  32. Zinberg NE: Drug, set, and setting: The basis for controlled intoxicant use. New Haven: Yale University Press, 1984.
  33. Brecher EM: Licit and illicit drugs. Boston-Toronto: Little, Brown and company, 1972: 321-334.
  34. Barendregt C: personal communication 1990.
  35. Kaplan CD, Vries M, Grund J-PC, Adriaans NFP: Protective factors: Dutch intervention, health determinants and the reorganization of addict life, in: Ghodse H, Kaplan CD & Mann RD (eds.): Drug misuse and dependence. Park Ridge, NJ: Parthenon Press, 1990: 151-161.

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