ABSTRACT
Introduction
Method
Severity - of - dependence scale
Results and discussion
Author: M. GOSSOP , M. BUTRON , M. MOLLA
Pages: 25 to 33
Creation Date: 1994/01/01
Drug-producing countries such as the Andean countries of South America where cocaine is manufactured are confronted by special difficulties associated with the widespread avail- ability of drugs. There have been few detailed reports of patterns of use in relation to the type and severity of cocaine dependence problems within those countries. The present study looks at the patterns of cocaine use in relation to severity of dependence among a clinical sample of South American cocaine users. Information about patterns of cocaine use and severity of dependence was collected from a sample of 68 drug users who were receiving treatment for cocaine problems at treatment centres in Bolivia and Peru. Levels of cocaine consumption were extremely high. The mean daily dose was 16,4 grams. The majority of the users (87 per cent) smoked cocaine in the form of pasta, pitillo or basuco. More than half of the sample reported using cocaine at least 20 times a day. Severity-of- dependence scale scores were high and these are consistent with the frequent and compulsive pattern of use reported within the sample. It is suggested that the more severe cocaine problems reported in South America compared to some western countries may be due to the substantial differences in the amounts of cocaine which are typically ingested. In the Bolivian sample most of the users were taking cocaine in amounts which greatly exceed those usually seen in western countries.
*The authors wish to thank Mario Argondona who provided the original idea for the present study and who helped in many practical ways during the investigation.
Drug-producing countries are confronted by special threats associated with the widespread availability of drugs. The production of illicit cocaine can have wide-reaching and serious effects upon the social and economic life of a country. The impact of cocaine production within Bolivia has been described by Healy [1] . Other producer countries have also been seriously affected by the production of other types of drugs. The production and distribution of heroin within Pakistan, for instance, has led to a situation in which the drug is easily and cheaply available throughout all parts of the country, and the explosive growth of heroin addiction since about 1980 has completely overwhelmed the few national treatment resources [2] .
The chewing of coca leaves is a long-established cultural tradition among millions of people in the central Andes region. Although there is some debate about the health risks associated with coca chewing, it is generally regarded as presenting only relatively minor health problems [[3] , [4] ]. The use of synthetic cocaine preparations and the administration of cocaine by smoking or injection, however, could be expected to lead to different and more serious consequences, and patterns of use which involve smoking cocaine paste have been reported as leading to many serious problems in South American countries [5] . Coca paste was uncommon in South America before the 1970s, but is now widely avail- able and used. Soon after its appearance, people with clinical problems associated with cocaine smoking began to be reported, and the numbers of people with such problems grew rapidly [6] .
Recent research has looked at beliefs and attitudes of drug users in Colombia [7] . However, despite the fact that the South American producing countries have been described as suffering from "some of the most severe cocaine -related problems to be observed anywhere" [5] , there have been comparatively few detailed investigations of the patterns of use in relation to the type and severity of cocaine dependence problems within those countries. The present study looks at the patterns of cocaine use in relation to severity of dependence upon the drug among South American cocaine users.
The sample consisted of a group of 68 drug users who were receiving treatment for cocaine problems at treatment centres at Cochabamba, Bolivia, and at Lima. The sample comprised 47 men and 21 women; they were aged between 17 and 53 years and the mean age was 29,3 years (standard deviation 6.0). Information about patterns of cocaine use was obtained by means of a structured interview conducted at entry to the clinics.
Severity of cocaine dependence was measured by the severity-of- dependence scale (SDS) presented below. All subjects completed the SDS [8] , which had been translated into Spanish and adapted for the measurement of dependence upon cocaine. The SDS provides a short, easily administered scale which can be used to measure the degree of dependence experienced by users of different types of drugs. The SDS contains five items, all of which are explicitly concerned with psycho- logical components of dependence. These are specifically concerned with impaired control over drug taking and with preoccupation and anxieties about drug use. The SDS has excellent psychometric properties and is suitable for the measurement of dependence with users of psycho- stimulant drugs; it has already been applied to users of both cocaine [9] and amphetamines [[10] , [11] ]. Although the SDS has not previously been used when translated in Spanish, there is no reason to assume that its properties would be altered.
Levels of cocaine consumption were extremely high, and amounts of up to 50 grams per day were reported. The mean daily dose was 16.4 grams and the modal dose 20 grams. The majority of the users (87 per cent) took cocaine in the form of pasta, pitillo or basuco and used it by smoking. Other users (13 per cent) took cocaine hydrochloride powder intranasally. The production of pasta is usually carried out under rather primitive technical conditions, often without the correct chemicals. However, despite the presence of many harmful chemical residues in pasta, the cocaine content in Bolivia and Peru is often high [12] , and usually varies between 60 per cent and 80 per cent [4] .
The majority of the South American sample used cocaine very frequently. The modal frequency for cocaine use was 20 times per day; more than half of the sample (53.8 per cent) reported using cocaine at least 20 or more times per day.
The sample size for the study was small, and the group was non- representative in so far as it was recruited at drug treatment centres. For those reasons, caution should be used in generalizing from the findings. However, the intensity of cocaine use among the South American sample stands in stark contrast to the mean daily doses of between 0.75 and about 1.7 grams for (non-clinical) samples of cocaine users in the United Kingdom of Great Britain and Northern Ireland [9] , where purity levels for smokable crack cocaine are usually above 80 per cent [8] . Similarly, a study of cocaine users at Barcelona, Rotterdam and Turin [13] found that only between 13 per cent and 36 per cent of their users were taking more than 15 grams of cocaine per month. The mean frequency of use among the European cocaine users was also much less. During periods of their heaviest use only about half of the European samples were taking cocaine on a daily basis, and within the United Kingdom sample, users were taking cocaine up to 5 times per day. The average age of first cocaine use in the present South American sample was 19.7 years (standard deviation 5.7). That is directly comparable to age of first use reported for the United Kingdom and other European cocaine users [[9] , [13] ].
The mean severity-of-dependence scale score for the South American cocaine users was 8.24 with a range of 2-14. The mean SDS score is much higher than has been found for users of cocaine in the United Kingdom, where mean SDS scores of about 4 have been reported [9] . Also, the distribution of scores for-the present South American cocaine users differed from that of the United Kingdom sample. The distribution shown in the figure shows an approximately normal distribution of scores, whereas the scores of the London cocaine users was strongly skewed towards the left, with the majority of users reporting no problems of dependence.
The total SDS scores for the South American sample of cocaine users indicate levels of dependence which are comparable to those reported by chronic heroin addicts who approach services for the treatment of dependence problems in the United Kingdom [14] . It can be inferred from those results that the cocaine users in the study were severely dependent upon cocaine. The high SDS scores are consistent with the high dose and extremely frequent and compulsive pattern of use reported within the sample.
The women in the South American sample reported more frequent daily use of cocaine than the men (t = 2.12, p < 0.05), and they reported using larger daily amounts of cocaine (t = 2.59, p < 0.05). However, there was no sex difference in the reported severity-of-dependence scores (t = 0.39, n.s.). There were no sex differences on any of the other drug use variables (type of cocaine use, route of administration, age of first use, duration of use etc.).
There was a modest relationship between SDS scores and the typical amount of cocaine consumed (r = 0.23, p < 0.05), but there was no relationship between SDS scores and frequency of cocaine use (r = 0.05,n.s.). The low correlation between dose and SDS scores and the lack of correlation between frequency of use and severity of dependence may at first seem somewhat surprising. However, it can (at least in part) be explained as being due to the subjects being drawn from a highly selected clinical sample in which the majority of subjects were using cocaine at such high doses and so frequently during a typical day that a ceiling effect would have operated to mask any such correlation.
In that respect, the finding is similar to that of a previous study of opiate users recruited from treatment agencies where no association was found between severity of dependence and duration of heroin use or daily heroin dose [15] . There are also other factors that may serve to mask such relationships between dependence and drug -taking behaviours. For example, the relationship between drug dosage and frequency of use, on the one hand, and severity of dependence, on the other, should not be seen as strictly linear [8] . Severity of dependence could be expected to peak at levels below the highest doses and frequencies of use of chronic users. Beyond a certain point, the use of higher or more frequent doses may be due to factors which are either partly or wholly independent of any dependence processes. One such factor may relate to the physical or economic availability of large quantities of a drug.
There have been a number of interesting but puzzling discrepancies between reports about the severity of problems experienced by cocaine users in South American countries, and, indeed, in some parts of the United States of America, and in European countries. Such national differences are intriguing but have received surprisingly little attention. Reports from North and South America have often described many users becoming severely dependent upon cocaine with intense craving and compulsive drug-seeking behaviour. Washton [16] has referred to cocaine's "extraordinarily high addiction potential" and to the intense cravings that "are so powerful as to override even basic survival instincts". However, reports from other countries, including Italy, Netherlands, Spain and the United Kingdom, have reported that patterns of cocaine use have been associated with fewer problems and lower levels of dependence [[13] , [9] ]. Even in North America, there have been studies which have found that only a minority of cocaine users develop dependence problems [[17] , [18] ].
It is increasingly clear, both from the present and from other studies, that a specific drug can produce different levels of dependence when used by different routes of administration [8, 9]. In the present study, SDS scores were related to the type of cocaine used, with pastasmokers scoring higher than intranasal users of cocaine hydrochloride. The mean SDS scores were 8.5 and 6.7 respectively (t = 1.96, p = 0.055). The difference falls just below the 5 per cent criterion of statistical significance, possibly because of the small number of subjects who were intranasal users of cocaine hydrochloride. However, the difference is directly comparable to the findings on route of drug administration reported for both cocaine and heroin in studies of United Kingdom drug users [[8] , [9] ].
However, the national discrepancies in findings about cocaine problems cannot be fully accounted for in terms of users taking cocaine by different routes of administration. The use of crack cocaine and of cocaine by intravenous injection (both of which may be likely to lead to more severe forms of dependence) are now frequent in the United Kingdom [9] but they do not appear to have led to problems of the severity described in many North and South American reports. Nor can the national discrepancies be attributed to the use of lower quality cocaine in Europe. Purity levels of between 50 and 90 per cent are typical for cocaine seizures in the United Kingdom, with purity levels of smokable, "crack" cocaine at 80 per cent or above [[19] , [8] ].
It seems more likely that the national discrepancies in severity of cocaine-related problems may be due to the substantial differences in the amounts of cocaine which are typically ingested by cocaine users in different societies. The South American cocaine users in this sample were consuming extremely large quantities of the drug and taking it with great frequency during periods of use. Even allowing for the fact that the sample was recruited from a clinical population, the amounts and frequency of use greatly exceed those usually seen in western countries [13] . The ability of the South American users to take such large amounts of cocaine is in itself evidence of the build up of tolerance to cocaine that must have occurred. The results of the present study are a contribution to the research literature about the nature of cocaine use and severity of cocaine dependence problems in the special circumstances of a cocaine producing country. It would be extremely useful to have further information about patterns of cocaine use and their relationship to a range of different types of drug problems in the South American producer countries.
K. Healy, "The boom within the crisis: some recent effects of foreign cocaine markets on Bolivian rural society and economy", in Coca and Cocaine: Effects on People and Policy in Latin America. Cultural Survival Report, No. 23, D. Pacini and C. Franquemont, eds. (New Hampshire, Bowker, 1986).
02M. Gossop, "The detoxification of high dose heroin users in Pakistan", Drug and Alcohol Dependence, vol. 24, 1989, pp. 143 - 150.
03T. Plowman, "Coca chewing and the botanical origins of coca in South America", in Coca and Cocaine Effects on People and Policy in Latin America. Cultural Survival Report, No. 23, D. Pacini and C. Franquemont, eds. (New Hampshire, Bowker, 1986).
04J. Negrete, "Cocaine problems in the coca-growing countries of South America", in Cocaine: Scientific and Social Dimensions, G. Bock and J. Whelan, eds. (Chichester, Wiley, 1992).
05J. Negrete, "The Andean region of South America: Indigenous coca chewing in the rural areas and coca paste smoking in the cities", in Drug Problems in the Sociocultural Context, G. Edwards and A. Arif, eds. (Geneva, World Health Organization, 1980).
06F. Jeri and J. Perez, Dependencia a la Cocaina en la Peru, monografia 4 (Lima, Centro de Informacion y Educacion para la Prevencion del Abuso de Drogas, 1990).
07A. Gomez, L. Eslava and E. Escobar, "What do Colombians consume? Bogota 1988-1992", Adicciones,vol. 5, 1993, pp. 247-256.
08M. Gossop and others, "Severity of dependence and route of administration of heroin, cocaine and amphetamines", British Journal of Addiction, vol. 87, 1992, pp. 1527-1536.
09M. Gossop and others, "Cocaine: patterns of use, route of administration, and severity of dependence", British Journal of Psychiatry, No. 164, 1994, pp. 660-664.
10S. Darke and others, "Transitions between routes of administration of regular amphetamine users", Addiction,in press.
11J. Hando and W. Hall, "HIV risk -taking behaviour among amphetamine users in Sydney, Australia, Addiction,vol. 89, 1994, pp. 79-85.
12J. Inciardi, "Beyond cocaine: basuco, crack, and other coca products", Contemporary Drug Problems, autumn issue, 1987, pp. 461-492.
13R. Bieleman and others, Lines Across Europe: Nature and Extent of Cocaine Use in Barcelona, Rotterdam and Turin (Amsterdam, Swets and Zeitlinger, 1993).
14P. Griffiths and others, "Reaching hidden populations of drug users by privileged access interviewers: methodological and practical issues", Addiction,vol. 88, 1993, pp. 1617-1626.
15G. Sutherland and others, "The measurement of opiate dependence", British Journal of Addiction, vol. 81, 1986, pp. 485-494.
16A. Washton, Cocaine Addiction (New York, Norton, 1989), p. 32.
17D. Waldorf, C. Reinarman and S. Murphy, Cocaine Changes: The Experience of Using and Quitting (Philadelphia, Temple University Press, 1991).
18P. Erickson and others, The Steel Drug (Lexington, Massachusetts, Lexington Books, 1987).
19Drug Misuse in Britain (London, Institute for the Study of Drug Dependence, 1992).