The spread of heroin abuse in a community


TABLE 1 Annual incidence of heroin usage
TABLE 2 Towns where the drug users were initiated


Author: R. de ALARC?N
Pages: 17 to 22
Creation Date: 1969/01/01

The spread of heroin abuse in a community

M.D., D.P.M. R. de ALARC?N
Medical Research Council, Clinical Psychiatry Research Unit, Graylingwell Hospital, Chichester, Sussex.

Work done so far on the epidemiology of drug dependence has been concerned with obtaining prevalence rates - that is, the number of known cases of drug abuse in a locality in a given period. While this method has been useful in revealing the extent of the condition, it sheds no light on other important public health problems such as the mode and rate of spread of drug abuse.

If drug abuse is seen as a practice that is transmitted from one person to another, it can be considered for operational purposes, as a contagious illness. This approach makes it possible to apply to its study the methods and terminology used in the epidemiology of infectious disease. When a high prevalence rate of heroin abuse is found, it becomes desirable - if the analogy with infectious disease is to be pursued - to obtain information on: ( a) incidence (rate of appearance of new cases in the community) and ( b) the source of contagion.

In 1967 a field survey was carried out in Crawley New Town soon after the first cases of heroin abuse among young people were referred to the psychiatric services. Crawley is a new town, 35 miles from London, with a population of 62,130 (Registrar General, 1966). The findings gave a prevalence rate for heroin abuse of 8.50/1,000 in the population aged 15 to 20 in 1967. The rate rose to 14.75/1,000 when only the males were considered [1] . This high rate seemed to merit further investigation. The yearly incidence was needed in order to find out whether the habit was spreading or decreasing - and also the source of contagion; was it in Crawley or elsewhere?

The frequency with which new cases were referred to the psychiatric clinic would not give the incidence, since new referrals need not mean new cases. An increase in the number of referrals could simply be an indication that general practitioners, and other sources of referral, had become more alert to the problem of drug abuse. However, both these questions could be answered if one were to know when each case was initiated to the use of heroin and by whom. Thus the moment of the first 'fix' (injection) would be considered the point at which each 'new case' appeared in the community.

This approach appeared extremely attractive on account of its simplicity and the results of its application are described below.


The names of all known drug users between the ages of 15-20 were taken from the register of the Crawley Psychiatric Service ( ibid). The following data were abstracted from the case notes of each patient: ( a) the date, or if this was not available, the month or year when he started taking heroin, ( b) the name of the person who had initiated him to the drug and the circumstances in which this occurred.

By the time this study was started it had become normal practice in the Crawley Psychiatric Service to record this information in the course of taking the clinical history of a new referral. It was only necessary therefore, to collect the data from the case notes and supplement it by direct questioning of those patients whose history had been taken before this practice had been established. In a number of instances the patients were unwilling at first to disclose the name of their initiator. However, most of them gave the name later during individual therapy sessions or in a therapeutic group with other heroin users.

It was also usual when taking the history to ask each of them for the names of any other youngsters whom they in turn had initiated. On this matter however, the majority were less forthcoming. Whenever they did tell us, the information proved to be a valuable check on the veracity of those who had given the names of their initiator.

When two or more other heroin users had been present at the time of the initiation, the person who actually gave the first injection was recorded as being the 'initiator' for the purpose of this study.

The patients in this study were interviewed during 1967 or the first three quarters of 1968. All patients who were initiated to heroin in 1968 have been excluded from this study, as well as four cases who attended the psychiatric service in 1967 but whose initiation data was not recorded at the time. So far it has not been possible to re-interview these four cases.

It should also be noted that during 1967 and 1968 no out-patient maintenance treatment with heroin was carried out either by general practitioners or the psychiatrists in the area.


The findings are depicted in the figure below which shows both the approximate date of the first injection of heroin and the chain of transmission from one subject to another for fifty-eight young people living in Crawley in 1967 who had experimented with heroin or were using it regularly. Two major trees of spread (A and B), two minor ones (G and J) and a few "non-attached" cases (C, D, E, F, H and I) are discerned.

There were fifty-three males and five females. All were aged between 15-20. Fifty-one had been seen in the psychiatric services and the information on the remaining seven (A7, A25, A26, BI0, B12, BI4 and Gl) was obtained from their 'initiator' in six instances and from the person initiated in one (Gl).

Forty-two patients gave the approximate date of their first injection of heroin and the name of their initiator. In sixteen of these this information was confirmed by the initiator himself. Eight refused to disclose the name of their initiator but mentioned when they had been initiated (cases Al, C1, DI, El, FI, HI, I1, Jl). Four of these (Al, CI, D1 and El) stated that they had been initiated while living out of Crawley by a person from the town in which they were staying. This is likely to be true as Al, C1 and D1 were initiated between 1962 and 1964 a period for which there is no evidence of cases in Crawley and El did not come to live in the area until 1967. Seven were mentioned by the initiator alone (cases A7, A25, A26, B5, BI0, B12 and B14) and no information was available on who initiated Gl.


It was not possible in all cases to point to the month of initiation but an over-all concentration of initiations was found in the second half of 1966 and the first half of 1967.

The number of first experiences per year with heroin among the fifty-eight cases recorded are given in table 1.

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TABLE 1 Annual incidence of heroin usage

Year of initiationPeople initiated
1963 .
1964 .
1965 .
Late 1965 or early 1966
Not known but before the end of 1966
Late 1966 or early 1967


The two major trees of spread (A and B) shown in the figure on page 18 cover a total of forty-eight young persons from Crawley. Among the remaining ten, transmission from one Crawley boy to another has only been established from G1 to G2 and from Jl to J2. J1 has not revealed the name of his initiator and Gl had not been interviewed.

It is quite likely that when further information is obtained it will be found that Gl and Jl have in fact been initiated by a member of the A or B streams. They belong to the same age and social group and Gl is known to have had infective hepatitis in June 1967 at a time when most of the Crawley drug users had an attack.

Cases Al, BI, B2 and B3 who are at the head of the two main streams were introduced to heroin by persons who were not from Crawley; the initiation took place in other towns (Worthing and Brighton). The same applies to C1, D1 and El. A total of forty-six initiations were known to be carried out by Crawley boys and not by outsiders.


As the investigation proceeded it became clear that it could also be useful to know the place where the initiation took place, and questions aimed at obtaining information on this point were included in the routine clinical history.

Though the data obtained on this point is as yet still incomplete the findings appear relevant enough to be reported and are shown in table 2.

TABLE 2 Towns where the drug users were initiated

TownNumber of initiations
Bognor Regis
Not known

Twenty-two cases were initiated in Crawley itself. All of them were living with their parents at the time, and nine of them had their first injection in their own home or that of another drug user. Among the rest, public toilets and pubs were the most popular places for their first experience. Two had it in a van parked in the street and one was initiated in a youth club. Seven of the nine cases who had their first injection in London had it administered by another Crawley drug user. It was common practice for several boys from Crawley to go down to London together by car or train on a Friday evening. All the seven cases were introduced to heroin in the course of these London visits. The initiation usually took place in the toilets at Piccadilly Circus or the premises of a club in Brixton. Five were initiated in Brighton, all of them between 1963 and early 1966. Two of them as well as the one in Bognor were initiated by Crawley boys.


Though this investigation was restricted to establishing when and through whom the first injection of heroin was taken and not the degree of dependence it should be noted that twenty of the fifty-eight cases in the series have received in-patient hospital treatment for severe heroin dependency and every one of the twenty-two cases who have had out-patient treatment have shown signs of dependence. Only three cases in this series are known to have given up heroin spontaneously after the first few injections.


There are several points about the source of information that may require some discussion. First, how accurately may a heroin user be expected to recall the first experience of an action which by now has become a regular habit? The memory of the first experience could be blurred by a long series of repeated experiences. This occurs with smoking and drinking where it is often impossible to recall the first cigarette or drink, specially after several years.

To this, one can say that when the first experience has taken place recently, and happens to have a particularly strong impact of its own, it is possible to recall not only the subjective effects but also the circumstances in which it took place. For example, a person could be expected to recall his first sexual experience or the first time he got drunk and experienced a hangover, if this event had taken place only two or three years previously. In the case of heroin, the first experience, the "virgin fix", is usually very intense; the patient will often describe it in glowing terms and with some nostalgia, and wishes he could experience it again even though it was accompanied by initial sickness and itching. Some patients were able to describe in detail the circumstances in which it took place, e.g. on New Year's Eve, at so and so's birthday party, etc. and give details of their own behaviour and that of others who were present at the time. It should be mentioned that the impact of the "virgin fix" appears to be less pronounced among those patients seen in 1968 who had been taking intravenous methedrine before experimenting with heroin. However, the information for this study was obtained before the use of methedrine became popular in Crawley and in the majority of cases within months or at most two years of the first experience. Only three out of the fifty-eight cases claim to have tried other drugs by injection previous to their first experience with heroin.

Second, how truthful are these patients? When their co-operation was enlisted previously for the prevalence study mentioned above and for a study of the signs and symptoms by which heroin abuse can be recognised [2] they were very helpful and when the information they provided was cross checked by various means it proved to be correct. For instance, in the prevalence study patients gave sixty-four names of people whom they claimed were on heroin. Thirty-five of these names were afterwards fully confirmed by other screening methods and five more were confirmed in 1968 when they appeared at the psychiatric service for treatment for heroin abuse.

In the present study, for sixteen out of the forty-eight cases who mention the name of their initiator it has been possible to obtain confirmation from the initiator himself. Of the seven names that were given only by the initiator, the girlfriend of one of the recruits confirmed the initiator.

When the dates of initiation were studied, inconsistencies were found in two cases (B4 and Al5). B4 claims to have taken heroin for the first time in February 1967, but on the other hand there is ample evidence that he initiated three people, perhaps four, in the second half of 1966; Al5 claims to have had his first injection in November 1966, though there is evidence he initiated Al7 in December 1965 and Al6 in June 1966. This could mean either that they were "pushing" heroin without taking it themselves or they wanted to give the impression that they had not been very long on heroin in order to avoid admission to hospital. With B4 and Al5 these two possibilities could be equally likely as both are described by other heroin users in terms that suggest that they are pathological liars, and clinically they showed psychopathic traits not found in most of the other patients. Al5 had been running a thriving business in drug peddling since the age of 13 when he started selling pep pills at school, and B4 was looked down on by the other heroin users for his practice of deliberately initiating boys younger than himself to heroin and other drugs.

Further confirmation of the reliability of the information these patients gave was that whenever they were asked again, after some weeks or months, when and by whom they were initiated they always mentioned the same person as on the previous occasion and there has never been a difference of more than one month as regards the date of initiation they gave on different occasions.

Another check on the date of initiation given by the patients or the initiators was to compare it with the date that the name of the heroin users was first elicited by one of the screening methods used in the 1967 prevalence study, e.g. date in which he had an attack of hepatitis, or his name was mentioned by another heroin user, or he was charged by the police etc. In no case did the date in which one of these methods brought out the name of the heroin user precede that given by the patient as being the moment of his initiation. However, as the exact month is not known in all cases, only the year of initiation and not the month is recorded in figure I.


Another point of methodological interest is whether the first experience with heroin indicates the beginning of heroin abuse. It seemed justified for the purpose of this study which only aims at recording the spread of heroin and not the development of dependence. Little is known as yet of the natural history of heroin abuse in the young. What factors are conducive to the habit becoming established? How many injections does it take? What role do the other drug users in the community play in re-inforcing the habit? These questions are at the moment being investigated further.


In so far as the fifty-eight cases shown in figure I represent the total "drug scene" in Crawley then there do not appear to have been any drug users or pushers coming in from London and other towns to "initiate" the young people of Crawley to the use of heroin between 1962 and 1967. From the information obtained it appears that heroin abuse was introduced into Crawley by local boys who had acquired the habit whilst visiting or living in another town. They then spread the habit among their peers. In every case between the initiators and the initiated there had been a long-standing or current link of common school and neighbourhood, or common haunts of amusement (pubs, dance halls, bowling alleys etc.). There is evidence that heroin users from nearby towns, e.g. Redhill and Horley, have visited Crawley regularly and there appears to be a certain degree of mutual interaction between the towns. These outsiders may play a part in perpetuating the habit either by bringing in supplies or by increasing the chances of the population at risk coming into contact with drug users when they come into the town. They are also known to have accompanied Crawley boys on their trips to London or to the seaside resorts. This possible mutual interaction between Crawley and other towns is at present being studied.


As far back as 1957, Morris [3] pointed out: "There are many interesting analogies between the dynamics of infectious disease and that of mental illness: from the dancing mania of the Middle Ages to epidemic benzedrine addiction." If heroin abuse is considered for operational purposes as an infectious disease, then when the yearly incidence figures depicted in figure I are studied, a pattern of spread appears to emerge, in which one can distinguish several stages:

1st stage 1962 to 1965 inclusive. A small number of people from Crawley experiment with heroin whilst living in other towns. Their histories reveal that the period between the first injection and the moment the habit became regular is long - up to one year - indicating perhaps a low density of heroin users in the population and consequently less opportunity for further contact with other drug users who could reinforce the initial experience.

2nd stage first half of 1966. A nucleus of young heroin users is formed, initiated by those who had acquired the habit during the previous stage. Not all of the latter acted as "initiators" but most of them acted as "reinforcers", either by providing a continuity of contact with those who recently experimented with heroin or by bringing supplies of the drug into the town and making it readily available to those who had not as yet learnt how to obtain it on their own in London. For instance, we have no evidence that case C1 who started taking heroin in 1963 whilst in Brighton, has ever initiated anyone else to heroin. On the other hand, we know for certain that he has been actively concerned in selling the drug in Crawley to those who were already using it. He claims that some weeks he would have a turn over of more than ?40.

3rd stage second half of 1966 and first half of 1967. The population at risk is in contact with a greater number of "initiators" and "reinforcers" and heroin abuse develops explosively in the community. As the habit extends in the town, the possibilities of contact with heroin users increase and one could venture a hypothesis that those youngsters predisposed by previous excessive use of other drugs, e.g. pep pills, or as Professor Paton [4] suggests, by a recent stress (bereavement, failure, etc.) would easily succumb.

During this third stage the average length of time between the first injection and regular use of the drug has become considerably shorter, indicating the effect of reinforcing agents, be they persons, or simply fashion.

This increase in heroin abuse in the second half of 1966, and the first half of 1967 is mirrored to a certain extent by the pattern of the incidence curve of infective hepatitis in the 15 to 20 years age group during this period. The first case of hepatitis appears in November 1966, from then onwards there is a gradual increase in the number of cases appearing each month, with an abrupt high peak in June 1967 and a progressive decline in the remaining months of the year. Due to the multiple sharing of syringes and needles and the length of the incubation period it is impossible, except in very rare instances, to trace the transmission of the infection from person to person.

Though the present study does not include all the confirmed cases of heroin abuse found in Crawley during 1967, nor those which the screening methods may have failed to disclose, the numbers prove high enough when checked against the 1967 prevalence figures for the findings to answer the questions posed at the beginning of the present study, i.e. what is the incidence? has it increased? and what is the source of contagion?

These findings provide now a baseline with which to compare, using the same methods, the rate of spread of heroin in Crawley during 1968 and form an idea of the direction heroin abuse is taking in the town. Unfortunately no similar studies have been carried out so far in other towns which would enable one to see if the trend observed in Crawley is merely an indication of what is happening in other parts of the country, or a phenomenon peculiar to the town itself.

Preliminary data suggest that the figure for 1968 will show a marked decline in the number of new cases of heroin abuse in Crawley. One would like to attribute this to a decline in fashion, but other factors are likely to play a part. The most important of these could be perhaps the new legislation on the prescribing of heroin. Other reasons could be the fact that several of the more dependent heroin users have moved to London and that in Crawley, as in other towns (Pierce-James [5] , Glatt [6] , Lancet[7] ) the use of heroin has been displaced partially or totally by intravenous methedrine. The problem is a polydrug one--very few patients restrict themselves to one drug only--and as Chapple and Gray [8] pointed out, the spectrum of drug abuse and the variety of drugs used appear to play a part in the degree of dependency found in each particular case. It must not be forgotten that established drug dependency is a chronic disease, and reverting to the analogy with the epidemiology of infectious diseases, as long as there are chronic cases with a population at risk, there is a possibility of another acute outbreak. It need not be heroin, it could be other drugs or combinations of drugs.


Epidemiological studies on drug abuse reported so far have been concerned only with establishing prevalence rates. Systematic research into incidence rates and paths of transmission of the habit have been neglected.

For operational purposes, the author has regarded drug abuse as a contagious illness and has applied the methods used in the epidemiology of infectious diseases to the study of heroin abuse in Crawley New Town, England, where a high prevalence rate was found in 1967.

By establishing the approximate date on which heroin users had their first injection of the drug and the identity of the person who had given them this injection, it was possible to discover both yearly incidence and source of contagion--date of first injection was thus considered the point in which a new case appeared in the locality. This information was obtained from fifty-eight users, aged 15 to 20, from 1962 (the earliest year in which a young Crawley heroin user is known to have been initiated) to 1967 inclusive. By plotting the yearly incidence during this period, three stages in the spread of heroin in the town emerge: (i) 1962-1965; a small number of Crawley youngsters are initiated in other towns; (ii) first half of 1966; a nucleus of established heroin users, initiated by the former, develops in Crawley; (iii) second semester 1966 - first semester 1967; heroin abuse spreads explosively in the town. Two major transmission trees covering forty-eight cases are traced; one of these trees includes thirty-two users who can be traced back to the original initiator; the other, sixteen users. The remaining ten cases have not yet been incorporated into these. Of the total fifty-eight initiations to heroin, forty-six were carried out by Crawley boys, seven were initiated in other towns and five have not disclosed their initiator. The methods used in this study are discussed in detail. The value of incidence studies for making predictions and for comparing trends in drug abuse from year to year and from place to place is stressed.



R. de Alarc?n, and N. H. Rathod, "Prevalence and Early Detection of Heroin Abuse", Brit. Med. J ., 1968, 2, 544.


N. H. Rathod, R. de Alarc?n and I. G. Thomson, "Signs of Heroin Usage Detected by Drug Users and their Parents", Lancet, 1967, 2, 1411.


T. N. Morris, Uses of Epidemiology , 1957, E. and S. Livingston Ltd., p. 61.


W. D. M. Paton, "Drug Dependence: A Socio-pharmacological Assessment", Advancement of Science , 1968, December, p. 9.


I. Pierce-James, "A Methylamphetamine Epidemic", Lancet, 1968, 1, 916.


M. Glatt, "Abuse of Methylamphetamine", Lancet, 1968, 2, 215.


Lancet, "Annotations", 1968, 2, 818.


P. A. L. Chapple, and G. Gray, "One Year's Work at a Centre for the Treatment of Addicted Patients", Lancet, 1968, 1. 908.


The author is greatly indebt to Drs. N. H. Rathod and I. G. Thomson who were jointly responsible with him for the clinical records on which this study was based.