Effects of legal restraint on the use of drugs: a review of empirical studies




Author: Reginald G. SMART
Pages: 55 to 65
Creation Date: 1976/01/01

Effects of legal restraint on the use of drugs: a review of empirical studies 1

Reginald G. SMART2

Serious efforts to control the production and use of drugs are about a century old. International agreements began chiefly in connexion with opium use in China. Controls on the use of opium, cannabis and other drugs began in earnest after 1909 in most developed countries, although China attempted opium controls around 1800. A wide variety of government interventions have been used in control efforts, but uncertainty exists about the value of most such interventions. The purpose of this review is to critically examine empirical studies of government efforts to change laws regarding: (i) the production and distribution of drugs; (ii) the penalties for users and traffickers; and (iii) the price of drugs. The concern is with how such changes affect actual drug use or the numbers of users. The broad aim is to indicate the areas of success and failure in legal restraints and to describe restraints for which empirical evidence does not seem to exist. The last aim is to determine whether any features unify the successful and unsuccessful attempts. The author has been unable to find a recent critical review of this area but only isolated studies.

Of course, a vast amount of supposition, theory and sheer rhetoric has been developed around the question of legal restraints. In this paper such contributions are ignored in favour of those having some data on the effect of the intervention. The theoretical aspects of general and specific deterrence and crime have been left for another review in favour of an analysis of empirical studies of legal interventions concerning drugs.

The ideal study would be one in which before and after measures were taken relevant to some effect in an area which had the restraint and in a similar one which did not. Such studies are rare and extremely difficult to do in the area of legal and social policy changes. The most novel study has before and after measurements but lacks a control area. A few are studies at one point in time with suppositions about what came before or after. None of the available studies utilize experimental or even quasi-experimental designs, as carefully controlled social policy studies in this area have apparently never been done. A further problem is to know how long an effect is expected to last and how to decide which of a set of changes is most important. This review encompasses studies of interventions related to the use of narcotics, marijuana, and prescription drugs. There is no interest taken in legal restraints on alcohol or tobacco sales (see Popham, et al., 1974 for a review of the alcohol area). Nor is interest taken in measures which did not have evidence of reducing or increasing actual drug use, or numbers of users. This review is based upon studies in the open literature and without access to secret or classified government reports bearing on the issue of legal restraints. Of course, it is not known whether such reports exist or whether they would affect the conclusions made.


Addiction Research Foundation, 33 Russell Street, Toronto M5S 2S1, Canada.


The author acknowledges the help of Lorne Salutin, Patricia Erickson, Jasper Woodcock, Richard Blum and John Ball in the preparation of this paper.


Although herculean national and international efforts have been expended to control narcotics only a very few such efforts have had any empirical evaluation. Great problems exist in assessing the effects of narcotics legislation on drug use in the USA. Only four sets of restraints appear to have substantial data indicating some effectiveness. The first would be the controls on ether drinking in Ulster during the mid 1800s. Another would be the heroin seizures made in the early part of 1972 and the effect they had on heroin addiction in the USA. Another would be the control of opium use in India in the 1950s. The last would be the introduction of heroin clinics into Britain in 1969. None of these governmental restraints is unidimensional or simply described and all present difficulties of interpretation and analysis.

At the beginning of the twentieth century a large number of narcotics addicts existed in the USA. Ball and Chambers (1970) have estimated the number at that time to be about 237,000. In 1914 the Harrison Narcotic Act was passed which licensed importers and manufacturers of opiates and effectively forbade the prescription of opiates to addicts by physicians. The effects of this and most other legislation on the extent of the narcotic problem in the USA cannot be easily assessed. Between 1914 and 1970 some 55 federal drug laws supplemented the Harrison Act plus hundreds passed by individual states (Brecher, 1972). In 1970, the NIMH estimated that about 250,000 addicts existed in the USA, hence a case for the value of the total system is difficult to make.

Ether drinking, a strange phenomenon, seems to have reached almost epidemic levels in Ulster in the 1840s. It began in 1842, chiefly in response to its very low price compared to alcohol. Ether was drunk with water, a few ounces at a time. It produced wind, quickened pulses, flushed faces, and, best of all, a rapid drunkenness which disappeared with the hour and without hangover symptoms. It was most popular among lower class males in a few catholic counties of Northern Ireland. At one time it was estimated that one-eighth of the population was using it regularly. In 1969, it began to be "cursed by the priest" and "no Catholic dare sell it" (Connell, 1965). The opposition of the Catholic church reduced its popularity somewhat, but in 1890, it was scheduled as a poison under an earlier Poisons Act (1870). Within months imports were down by 80 per cent and almost disappeared by the year 1900, with only rare cases later. Ether was never made in the Irish Countries in which it was most popular and imports from Britain and Southern Ireland could be easily stopped under the Poisons Act. Apparently, illicit manufacture or distribution was never a serious problem. The legal restraint worked in concert with religious persuasion and the relative value of each is difficult to assess, although the strongest influence would seem to have been the Poisons Act. This is one of the very few instances where scheduling a narcotic as a poison had remarkable effects on its use.

One of the most impressive narcotics control programmes has been conducted in India (Kohli, 1966). After achieving independence in 1947 the Indian Government decided that opium poppy cultivation for other than medical reasons should cease within 10 years. A large programme was launched in which the area under cultivation was reduced by about 25 per cent, the number of cultivators by 60 per cent, with licences issued to each. Cash incentives were given to cultivators to discourage their selling opium on the illicit market. Increased efforts to stop trafficking also occurred. The number of opium addicts is reported to have dropped from 432,609 in 1958 (the first year of registration) to only 121,178 by 1964. Opium seizures also fell remarkably between 1958 and 1964.

One of the best documented effects of legal restraints occurred in 1972 when the first real shortage of heroin appeared in the USA since the Second World War. Both Ingersoll (1973) and Cusack (1974) have described the shortage and its consequences. In early 1972 a variety of heroin seizures occurred in the USA, totalling some 200 kilos. Several French laboratories were seized and a record 400 kilo seizure was made of heroin destined for the US market. A variety of enforcement efforts resulted in seizures in Latin America and in the extradition of a prominent trafficker. By the middle of 1972 a serious heroin shortage occurred which lasted at least partly into 1973. Ingersoll (1973) has stated that the shortage had the following effects in the USA:

  1. increase in price of heroin;

  2. reduction in purity of street heroin;

  3. increased diversion of controlled drugs e.g. burglaries (presumably of pharmacies), false prescriptions;

  4. increase in addicts seeking treatment, then a decrease;

  5. seeking of heroin substitutes by addicts;

  6. decline in drug-related deaths.

In fact, data were presented only for increases in price, reductions in purity and for heroin-related deaths. Purity appears to have decreased by varying amounts in different cities, from 15 per cent to over 100 per cent. Price per milligram increased by 90 per cent to 800 per cent in different areas. Heroin related deaths are more difficult to interpret. Most areas showed a reduction over 1971, but no trend analysis is presented. Deaths actually increased in New York and Philadelphia, two cities which should have been most affected by the shortage. Whether this change is more than a cyclic fluctuation is difficult to say from Ingersoll's paper.

A further problem is in interpreting the reason for any change. Ingersoll makes no mention of poppy crop reductions in Turkey. However, Cusack (1974) noted that between 1968 and 1971 production of opium in Turkey (the main source for the US market) had been reduced and "by 1972 opium production in Turkey had been sufficiently reduced to bring some relief and with no opium crop in 1973, the shortage of heroin which began in mid-1972 increased and remains to the present". Cusack appears to attribute the increases in street price, reductions in purity and decreases in addicts to the reduction of the Turkish crops rather than to the seizures made. In fact, the crop reductions may have had little impact at any time because of the amounts stockpiled earlier. Some $35 millions was given by the USA for crop substitution programmes in Turkey. However, it is obvious that a variety of police, administrative and agricultural restraints were operating at the same time to create the reduction in indicators of heroin addiction. The separate value of increased police seizures, breaking up of laboratories and crop substitution cannot be determined from the 1973 heroin shortage in the USA. One could claim, rather unconvincingly it seems, that all of these taken together created a peculiarly effective combination with drastic effects. Conclusions about the value of any particular legal restraint are difficult to make.

The development of drug treatment centres in Britain during 1968 and 1969 also contained elements of both legal restraint and treatment. Much has been written about the British system or lack of it and all such writing cannot be referred to here (e.g. Bewley, 1972; Hawks, 1973; Smart, 1974; Johnson, 1975). However, a brief review of the restraints introduced in 1968 and their effects is attempted.

The Second Brain Committee found that in the mid-1960s heroin addiction was increasing, especially among young persons, that much of the illicit heroin came from legitimate prescriptions issued by physicians and that about a half dozen physicians were doing most of the over-prescribing.The Brain Committee made several recommendations which increased controls and made treatment more available. The results were:

  1. Notification of addicts to a Central Registry was made compulsory for physicians: it had been voluntary before.

  2. A variety of small treatment centres was established i.e. the British Clinics: about 25 are now operating.

  3. Physicians were especially licensed to prescribe opiates and cocaine: only those in clinics and hospitals were allowed to prescribe heroin.

  4. A committee continually reviewed problems of addiction and its treatment.

  5. A rehabilitative rather than a maintenance role was established for the clinics. This meant that prescribed heroin doses were reduced for all addicts in treatment and that methadone was more often used with new patients than was heroin.

  6. A system of giving prescriptions through individual pharmacies was developed, rather than giving long running scripts to individual patients.

Since all of these changes occurred within a short period of time the exact effect of any one of them cannot be easily assessed. Was the notification system more important than the licensing? Were the clinic prescribing policies of most benefit? Unfortunately, the chances of actually knowing the answers are remote.

The effectiveness of the whole system has been a matter of debate for some time: one's assessment of "effectiveness" depends upon the criteria chosen. The most frequently used criteria are:

  1. numbers of new notifications of adults;

  2. heroin related crime e.g. possession and trafficking;

  3. seizures of illegal drugs.

It is almost impossible to use the notification statistics to assess the system: notification was not compulsory prior to 1968. When it was required "new notifications" went up as expected-from 664 in 1967 to 1,476 and 1,030 in 1968 and 1969. If these years are seen as abnormal (because of getting known addicts into the records) and 1970 is seen as the first "normal" year the system is not very effective. New notifications increased from 711 in 1970 to 807 in 1973. Incidentally, many people doubt whether the notifications system accurately reflects new cases in the population (see Smart, 1974 for a review). Convictions for opium under the Dangerous Drug Act (1965) went from 73 in 1968 to 98 in 1972. Convictions involving all opiates and cocaine possession increased from 464 in 1967 to 1,250 in 1972 and 1,868 in 1973. Seizures of heroin also increased remarkably (435 g in 1968 to 13,100 g in 1972 and 3,205 g in 1973).

In total, the available data do not guarantee that the changes made in 1968 have decreased the total heroin problem They may have created a decline in numbers of new cases but the available data on notifications are difficult to interpret. A concomitant problem has been the increase in importing and illegal possession of heroin. Of course which of the various new procedures may have been most or least effective cannot be answered. Conclusions on the total effectiveness of the 1968 changes in Britain are impossible to make.


Only a few studies are available concerning legal restraints and cannabis, and none have adequate controls.

A description has been made of the rather strange extinction of the charas traffic in India. (United Nations, 1953.) Traditionally, three forms of cannabis were used in India, i.e. charas, ganja and bhang. In the 1930s the Government permitted the importation of 70,000 kg from China. In 1936, the Government of Sinkiang (the major exporter) voluntarily stopped the export of charas to India, in keeping with the general aims of reducing world narcotic traffic. This importation was legal under all existing conventions and the decision to decrease it was not made by India. The ban did not become fully effective until 1939, partly because existing stocks were so high. After 1939 stocks decreased as did the consumption of charas from 59,800 kg in 1937 to 11,891 in 1942 and 0 in 1946. However, ganja consumption increased from 165,752 kg in 1937 to 214,660 kg in 1946.This was a 30 per cent increase. Bhang consumption increased 49 per cent between 1937 and 1946. Probably a simple substitution was being made because of the ban on exporting charas.

McGlothlin et al. (1970) made an indirect investigation of "Operation Intercept". This was a programme established by various American police forces to reduce the amount of marijuana being imported into the country, by means of increasing seizures, burning marijuana crops and the like. McGlothlin interviewed 478 university students and 116 patients in a free clinic during "Intercept" about their drug supply problems. The classes used were probably not representative in that they contained too many cannabis users. About 44 per cent of students and 51 per cent of patients using cannabis 10 or more times said that their use was below normal during "Intercept". Of those finding a cannabis shortage 76 per cent of students and 84 per cent of patients reported substituting other drugs. The most popular substitutes for marijuana were hashish, alcohol, hallucinogens and to a lesser extent stimulants and sedatives3. The price of cannabis in the area of the study was also reported to have increased by 17 per cent.

An interesting but perplexing study has been made of a change in the cannabis law in Oregon (Drug Abuse Council, 1974). The law was changed in 1973 to remove "criminal penalties" for possession of cannabis. For possession of 1 ounce or less there is a maximum civil fine of $100; no jail term is possible and there is no criminal record. A representative sample of 802 persons one year after the law was changed indicated that only 6 per cent used cannabis for less that 1 year: about 5 per cent indicated that they had increased their use in the past year and 40 per cent had decreased it. The report concludes that "it appears that the number of individuals using marijuana has not significantly increased in Oregon during the year since it has removed criminal penalties". This conclusion is not justified and would have to be based on pre- and post-data which were apparently not collected. No information is given about changes in conviction rates, cannabis seizures or other statistics which would indirectly indicate whether the law had increased cannabis usage.


Gooberman (1974) also interviewed users in the United States during "Intercept" and reached similar conclusions to McGlothlin et al. but the data are presented in a somewhat impressionistic manner, with few details on the methods actually used or the exact results obtained.

During the past few years cannabis laws have been changed in Canada, chiefly those concerning sentencing and penalties. Erickson and Smart (1975) have reviewed these changes at length. Briefly, the major changes were that in 1969 summary proceedings were allowed for simple possession, with sentences limited to a 6 months jail term and/or a fine up to $1,000for the first offence. Previously such offences were indictable and carried a jail term up to 7 years but about 50 per cent received a suspended sentence and probation. This "softening" in the law was followed by an increase in convictions from 2,313 in 1969 to 5,419 in 1970 and 8,389 in 1971.

During 1972, a discharge provision allowed the Canadian courts to convict cannabis offenders, without actually registering the conviction, with or without probation. Offenders could apply to have their criminal records removed and to be pardoned. Discharges were recommended only for first offenders but when implemented some recidivists also received discharges. This provision too was followed by a large increase in convictions. Between 1972 and 1973, arrests more than doubled and convictions for possession increased by 78 per cent. It appears that in Canada efforts to reduce penalties and "decriminalize" marijuana use have led to more convictions actually being registered. It has been speculated that as severe laws are tempered "it increases the willingness of police to charge, the prosecutor to prosecute and the judge to convict". It should be noted that a variety of studies done in Canada (Smart and Fejer, 1974; Leon, 1974) have shown that cannabis use increased in the population during the time when the laws were being softened.


Several successful efforts have been made to apply legal restraints to epidemics of prescription drug use. All of those which are well described involve amphetamines and the control of sudden epidemics of use, rather than endemic use. Epidemics have been controlled partly by legal restraints and other means in Japan, England, the USA, and Sweden.

The best known amphetamine epidemic is probably the Japanese methamphetamine epidemic of the early 1950s. The nature and course of this epidemic has been described by Brill and Hirose (1960) and Morimoto (1957). After the Second World War a large amount of amphetamines was dumped on the Japanese market. It could be bought in injectible form over the counter in the 1940s or illegally between 1948 and 1957 the end of the epidemic. By the peak in 1954, it was estimated to involve some 2,000,000 persons (Brill and Hirose, 1969). Control of the epidemic is sometimes attributed to the severe legal restraints imposed on the production and sale of amphetamines. A series of laws passed from 1949 to 1956 imposed;

  1. controls over the possession and distribution of amphetamines and other stimulant drugs;

  2. total restrictions on the use of amphetamines except for medical treatment and research;

  3. heavy fines and jail terms for illegal manufacture, possession and distribution. Numbers of persons arrested under the Awakening Drug Control Law fell from 55,664 in 1954 to 32,143 in 1955, 5,233 in 1956 and 803 in 1957.

Legal restraints, educational and treatment methods were developed, as well as a wide variety of school programmes for children. Large numbers of posters, leaflets, pamphlets and films about amphetamine abuse were also distributed Morimoto, 1957). Educational campaigns were held with factory workers, entertainment workers and those in correctional institutions.

Medical treatment was made compulsory for some Japanese addicts and the number of beds available increased from 250 in 1954 to 2,100 in 1955.

There can be little doubt that the total effort expended on all measures reduced the epidemic to manageable proportions. However, the relative contribution of legal, education and rehabilitative measures has apparently not been assessed. As usual, it is impossible to conclude much about legal restraint per se.

A somewhat better case for the effects of a "semi-legal" restraint can be made in the British methedrine epidemic. De Alarcon (1972) has described how changes in the availability of methylamphetamine (methedrine) affected an epidemic of usage. Frequent use of methedrine had become a major concern in Britain in 1967 and 1968. The British Medical Association, the Ministry of Health and the major manufacturers agreed in 1968 to "reduce production, withdraw the drug from retail pharmacists and restrict its supply exclusively to hospitals". These measures were not essentially legally enforceable but the involvement of the Government in the discussion probably made them appear to have the same force as legal ones. The effects of the measure were apparently not confounded by major educational programmes, changes in treatment policies, or other legal changes respecting the drug. De Alarcon's study, therefore, allows an assessment of the legal restraint largely on its own merits. Since the restraints were informal they could be implemented quickly and with little publicity.

De Alarcon (1972) was conducting a longitudinal study of drug abuse in an area south of London at the time of the methedrine restriction. A dramatic fall in methedrine use was found in his sample of 800 drug abusers. About 40 injected methedrine regularly prior to July 1968, but by 1969 only 2 were doing so. The price of ampoules went up sharply but almost none was available on the street during 1969 and 1970. Court appearances for possession of methedrine totally disappeared after the restrictions. It appears from this study that the closing of the retail market and the scarcity of the drug was responsible for the disappearance of methedrine injecting. Other factors, related to demand may have had some importance but interviews with users suggested that this was not the case. There is also the very close association in time between the restrictions and the disappearance of cases in October 1968. Substitute drugs were apparently not used by the abusers whom De Alarcon interviewed. However, De Alarcon studied multi-drug users and presumably their use of other drugs was not affected by the methedrine ban, that is no complete cure would have been established.

A similar epidemic has been described by Greene and Dupont (1973), although the interpretation of the value of legal restraints is a little more difficult. During 1972 there occurred an "explosive increase" in amphetamine use among heroin addicts in the District of Columbia. Much of the reason came from a reduction in the availability and quality of street heroin. Amphetamines (chiefly tablets) were obtained primarily from a small group of high prescribing physicians (6 of them wrote 12,602 amphetamine prescriptions in a few months) and from retail pharmacies which supplied heroin dealers.

In September, 1972, members of treatment agencies, the police and the local medical society formulated a control strategy. Drug manufacturers reduced shipments of amphetamines into Washington. Guidelines for physicians restricted amphetamine prescribing to narcolepsy and hyperactivity in children and a single high prescribing physician received "a harsh sentence". Considerable publicity and news coverage attended the operation of the control measures. During the 3 months after the measures were introduced a variety of indicators of amphetamine use declined. Urine-positives declined from 36.3 to 17 per cent at a treatment centre and from 17.6 to 5.0 per cent for court cases. Prices rose from $3.61 per tablet to $8.30 and users stated that they were difficult to purchase. It would appear, as in the British methedrine epidemic, that the control measures were chiefly responsible, rather than educational or rehabilitative efforts. Again, the restriction affected (as in De Alarcon's report) only one type of drug use amongst users who probably took many types of drugs.

A very detailed study has been made by Bejerot (1975) of efforts to control the use of "central" stimulants in Sweden. Unlike most other areas of the world Sweden had several discrete periods of time varying in the amount of restriction on the prescribing of stimulants. The periods were as follows:

  1. Prior to April 1965: "traditional restrictive drug policy". Ambulatory prescribing of stimulants to addicts was extremely rare and allowed in only a few cases.

  2. April 1965 to June 1967: "Permissive drug policy". An intensive prescribing began which involved about 10 physicians and more than 200 patients. They were chiefly intravenous stimulant users but some also used opiates. A large supply of legally supplied drugs became available among these patients and these drugs could be given or sold to other addicts or to neophyte users. More than 6 million doses of stimulants were prescribed during 1966.

  3. July 1967 to December 1968: Traditional restrictive drug policy. The prescribing of central stimulants was greatly reduced and they could be prescribed only on licence and "not on the indication of abuse". Maximum penalties for narcotic offences were increased (doubled in most cases) and the size of the national police forces working on the illicit drug trade was more than doubled.

  4. January 1969 to 30 June 1970: extra restrictive drug policy. Prescribing practices were not changed but penalties for narcotic offences were increased again. The size of the police force working on illicit trade also increased by a factor of 4.6 from 1968 to 1969. A large amount of data indicated that arrests for drug offences and initiation of drug use was greatest during the permissive period, less during the traditional restrictive and least during the extra restrictive. By the end of 1970 the initiation of new cases of intravenous abuse was very low (below 25 new cases). This study, as did De Alarcon's, involved changing prescribing habits of physicians, a group which is small and easily controlled compared to illicit traffickers. However, the effectiveness of the change in prescribing practices is more difficult to interpret because of the concomitant legal changes and the increased police activity on drug cases.


Empirical evidence on legal charges is so sparse that the field of the unknown is far greater than that of the known. We have virtually no information on any restraint acting alone, except for a reduction in legal supplies of methedrine and amphetamines. Most restraints have been studied in connexion with educational or rehabilitative efforts, or have been applied in such profusion that the value of any one, is lost in a total effect.

Numerous types of restraint are apparently completely unknown in their unique effects. In the area of production we could list crop substitution programmes, acreage controls, and licensing arrangements for manufacturers. Virtually nothing is known of the effects of increasing legal penalties for narcotic or cannabis possession or trafficking, requiring jail rather than fines, compulsory treatment, civil commitment and the like. No analysis whatever can be found of the effects of police activities such as drug raids, sweeps, search and seizure laws, increased surveillance, or increasing the size of drug squads. Further, no information seems available on the effects on drug use of international treaties such as the various International Conventions on Narcotics, or the 1,971 Convention on Psychotropic Substances.

At present, we are without firm information on the effects of any legislation (except Operation Intercept which did not involve new legislation) designed to decrease cannabis use or the use of psychoactive drugs, other than stimulants.


Despite the long history of legal restraints on drug use little can be concluded with any certainty from the empirical studies available. Doubtless, part of the reason for this is that methodological problems have never been solved or even foreseen by those wishing answers to the question of effectiveness. Legal changes respecting drug control are often haphazardly applied, with no plan to systematically evaluate effectiveness. Few have been applied in given areas but not others so that comparisons could be made. Cross-national comparisons are often difficult because so many legal changes are international rather than local. When such comparisons are possible it is difficult to be sure that demand for the drugs controlled started and continued at the same point in the affected and comparison country. These problems have meant that a few barely interpretable studies have usually been made, that none are ideal and that a very few allow any firm conclusion at all.

From the evidence currently available it can be tentatively concluded that:

  1. Successful attempts to reduce the supply of heroin, by means of seizures and crop reductions have produced reductions in illicit heroin availability, heroin addiction and deaths from heroin. However such reductions are sometimes small and so far no set of legal restraints has reduced the heroin problem to a negligible level.

  2. The effectiveness of the British heroin clinic system cannot be stated with any certainty.

  3. Large reductions in cannabis availability can probably reduce cannabis consumption, at least temporarily but probably with the substitution of other drugs.

  4. Legal restraints may have their greatest impact when they are combined with educational and rehabilitative efforts as in the Japanese amphetamine epidemic.

  5. The greatest successes in legal restraint appear to involve legal drugs. The British, American and Swedish amphetamine epidemics probably represent the best documented cases where legal restraints alone led to the virtual disappearance of a drug problem. In all cases concerted action was taken to get legal suppliers and/or physicians to modify their practices.

In general, it appears that legal restraints work best where legal drug distribution is being controlled by bringing pressure to bear on ethically motivated and well regulated agencies e.g. the pharmaceutical industry and physicians. Successful legal restraints which reduce illegal drug use such as heroin, cocaine and cannabis by controlling illegal agencies e.g. importers and traffickers have not been as well developed, so far as their empirical effects are known.


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