Introduction to Substance Use Disorders

Introduction to substance use disorders.

Topics covered:

  • Historical review
  • Legal control of recreational drugs
  • Consequences of drug use for young people
  • Who uses drugs and why?
  • Do school prevention programmes work?
  • What is meant by the harm-reduction approach? 
  • References

Historical review

The yearning to escape reality through intoxication, to enter, albeit briefly, an ‘Artificial Paradise', (1) finds expression in the earliest cave drawings, but traces of hallucinogenic black henbane found at sites of mesolithic settlement demonstrate that it predates the ability to record the experience.

The hardy annual which Linnaeus labelled Cannabis sativa in 1753 was probably the first non-food crop. A detailed account of its medicinal powers appeared in China almost 5000 years ago, and it subsequently found its way into the pharmacopoeias of each succeeding civilization, including our own. The fibrous stem of the plant was used for rope-making and weaving, and the seeds were a source of oil for food and fuel. ‘Indian hemp' reached Europe about 1000 years ago in the pouches of Moorish invaders of Spain and Portugal. It gradually gained a reputation as a rival panacea to opium, but it was not until the eighteenth century that it became a mainstream medicine in Britain and the United States. Recreational use was popular among European artists and intellectuals in the mid-nineteenth century, but in the United States its association in the public mind with the poorest immigrants from Mexico and elswhere demonized its image.

The opium poppy has been the source of humankind's greatest comfort and scourge. From its roots in the pharmacopoeias of the Egyptians, Sumerians, Persians, Greeks, and Romans opium was borne along the arteries of commerce into India, China, and finally Europe in the baggage of returning crusaders at the end of the last millenium. Paracelsus invented a mixture of opium, alcohol, and spices which he called ‘laudanum', and this mixture soothed and tormented millions of Europeans over the next 400 years. The conquest of Bengal in 1773 gave Britain a monopoly of Indian opium, which the East India Company aggressively exported to China in exchange for vast quantities of high-quality tea to feed the insatiable British appetite.

The Opium Wars which resulted from the Chinese emperor's discontentment at being saddled with 20 million new addicts led to the additional bonus for the British of the ceding of Hong Kong island as a colony ‘in perpetuity'. The drug reached North America with the first European settlers, and the first opium-containing patent medicine appeared as early as 1796. American entrepreneurial spirit ensured that by the end of the nineteenth century more than 50 000 such products were available, and the foundations for some collosal modern fortunes were laid in those unregulated times. Concerns about morphine addiction grew, and in 1898 a new treatment was triumphantly introduced—heroin.

The founders of the Babylonian empire were brewing beer 4000 years before the birth of Christ. Wine-making was first described in Egypt, and viticulture had extended throughout Europe by 2500 BC, partially displacing hemp and opium cultivation by Stone Age farmers. The ancient Greeks developed the Symposium as a means of containing heavy drinking within a structure of ritual, and public drunkenness was unusual. But Dionysus evolved into Bacchus; by Nero's time (AD 54) heavy daily drinking was the norm and fuelled the growing atmosphere of savagery and decay.

Although the Christian approach to alcohol has always been ambiguous, it was the Christian monasteries which safeguarded the traditions of brewing and viticulture when the Roman Empire collapsed. But around the same time (AD 616) adherents of Islam were forbidden alcohol by the sacred Koran of Mohammed. The process of distillation originated in the Middle East around the twelfth century, but it was not for another 400 years that aqua vitae became easily available alongside wine and beer. Wine-making had become a vast industry in southern Europe, but a new era began in the last quarter of the eighteenth century when Franciscan monks began laying out the Californian vineyards which would form the starting point for the New World wine tradition.

There is no way of knowing when North American Indians might first have incorporated tobacco into social and religious rituals, but the custom was well established by the time Christopher Columbus arrived in 1492. Returning sailors brought back the original duty-free supplies, and tobacco smoking became widespread in mainland Europe. Sir John Hawkins probably imported tobacco to England around 1550, but Sir Walter Raleigh is credited with its popularization throughout society. No country has ever been successful in suppressing tobacco use once the habit has become established, despite dire penalties: hand and foot crushing in Turkey, nostril slitting in Russia, total confiscation of assets in Japan, and a gargle with molten lead in Persia.

Chewing coca leaves has been endemic among South American indians for several thousand years, but it was not until the sixteenth century that coca became known in Europe through the writings of an Italian physician who had observed its use in Peru. Cocaine was isolated in 1859, and soon formed the basis for a plethora of tonics and patent medicines. These rapidly became popular in the United States after 1880 and at about the same time cocaine emerged dramatically as a mainstream medicine. Some practitioners saw it as a veritable wonder-drug, among them Sigmund Freud who wrote a ‘song of praise to this magical substance'.

According to an advertisement, cocaine could ‘ the place of food, make the coward brave, the silent eloquent, free the victims of alcohol and opium from their bondage...'. Coca-Cola, with a few milligrams in each glassful, was introduced in 1886. Unfortunately, an increasing number people chose to snort or inject cocaine in large amounts, horror stories multiplied, and within a decade or so the public image of the drug had plummetted. Freud moved on to pastures new and caffeine replaced cocaine in Coca-Cola in 1903.

Hallucinogenic substances have been used since prehistory in social and religious rituals. South American shrubs and roots, the skin of certain toads, psilocybin-containing mushrooms, the peyote cactus, mescal beans, thorn apple, sweet flag, deadly nightshade, mandrake root, morning glory seeds, black henbane, jimsonweed—shamans, sorcerers, and witches have never been short of materials able to provide a short-cut to the spirit world. Mystics, including the Delphic Oracle, used naturally ocurring gases or emissions, as well as fumes from perfumes and burning spices, to induce visions and trance states. Peyote extract found its way into some patent medicines, but until Bohemian circles in European cities discovered mescaline soon after its isolation in 1890 purely recreational use was unusual. Albert Hoffman changed all that with the serendipitous discovery of his ‘problem child'—lysergic acid diethylamide-25—in 1943.

Legal control of recreational drugs

Until the middle of the nineteenth century there was a free market in drugs in Europe and the United States, with access to everything from alcohol to opium and coca restricted only by the depth of one's pocket. Two developments did much to upset the status quo. In 1805, a pharmacist's apprentice separated a chemical from raw opium and named it morphine after the Greek god of dreams. Isolation of codeine, thebaine, and papaverine soon followed. Then in 1858 a Scottish surgeon invented a device that could deliver a dose of morphine directly to the point of pain, and this became known as a hypodermic syringe. The combination of powerful synthetic drugs and parenteral routes of administration greatly increased the scope for abuse. Combatants on both sides of the American Civil War were issued with morphine and syringes, and for many years afterwards morphine addiction was known as the ‘soldiers' disease's.

In Britain, opium dependency was recognized but generally not vilified, although this tolerance extended only to ‘opium eaters'; smoking the drug was regarded as a rather vile alien indulgence (as in the United States). Doctors were keen to get into the act, and the medicalization of addiction coincided neatly with the birth of the new specialism of ‘psychiatry', which sought to redefine interpersonal and social problems according to moral and medical principles. Concern was growing about the mortality among children sedated with opium when left unattended by women whose efforts fuelled the Industrial Revolution. But the main drive towards the introduction of the Pharmacy Act 1868, which also restricted sales of cocaine, was professional self-interest. Why allow grocers to corner such a profitable market? Controls over patent medicines soon followed, and the Act was made still more restrictive in 1908.

Such controls were slower to arrive in the United States, but in 1906 the Federal Pure Food and Drug Act required ingredients to be specified on the label. Public concern about opiates made the issue a vote winner, and importation of smoking opium became illegal in 1909. America was instrumental in organizing international conferences in Shanghai and The Hague, and in 1912 it was agreed that the 30 participating countries should enact legislation to restrict opiates and cocaine to medical indications on prescription only.

The Harrison Act duly entered the United States's statute book in 1914. Then in 1919 the Supreme Court ruled that maintenance prescriptions of morphine or cocaine to addicts did not constitute acceptable medical practice, and a punitive response to addiction was established which lasted until the HIV epidemic in the 1980s forced a change in philosophy. This coercive approach to recreational drugs gathered momentum. A national prohibition of alcohol was enacted in 1919 and was only repealed in 1933 because of a desperate need by the Roosevelt administration for taxation income. Many states banned cannabis, and its use was effectively outlawed nationwide by the Marijuana Tax Act 1937. By the same year, the majority of states had adopted the Uniform Drug Act to standardize their approach to recreational drugs. In a further effort to overcome what was regarded as a fragmented approach to enforcement, the Comprehensive Drug Abuse Prevention and Control Act came into force in 1970. 

In Britain, the Establishment was startled out of its laissez-faire position during the First World War by the discovery that soldiers were finding life in the trenches more bearable if they had a supply of cocaine to take back after leave in London. The Defence of the Realm Act Regulation 40B (1916) prohibited sale of cocaine or opiates to soldiers. After some fairly sordid newspaper reports of London nightlife in the immediate postwar period, including lurid descriptions of the drug-related death of a well-known actress, this entered civil law as the Dangerous Drugs Act 1920. For a while, the response to drug problems looked set to follow the American penal route, but in 1926 the government-appointed Rolleston Committee recommended that addiction should be regarded as an illness rather than a crime. Long-term maintenance on an opiate prescription for addicts who were unable to abstain was validated, and the ‘British system' was born. In deference to the 1925 Geneva Convention, cannabis was outlawed in 1928 but prescription remained possible until final prohibition under the Misuse of Drugs Act 1971.

The United Nations Commission on Narcotic Drugs (UNCND) was established in 1946 to take over from the League of Nations the determination of policy for international drug control. The signatory nations to the Single Convention on Narcotic Drugs (1961) and the Convention on Psychotropic Substances (1971) are required to ‘limit to medical and scientific purposes the cultivation, production, manufacture, export, import, distribution of, trade in, use and possession of' a long list of drugs which includes opiates, cannabis, stimulants, sedatives, and hallucinogens. UNCND has delegates from each member state of the United Nations and all other signatories of the 1961 Convention.

Most governments are firmly against arguments for legalization or decriminalization, but the Dutch have pioneered a different approach. In 1976, a policy of non-enforcement was initiated whereby possession or trade in small amounts of cannabis (<30 g) would no longer be prosecuted. The impact of this policy has been assessed by MacCoun and Reuter. (2) Between 1976 and 1983 depenalization resulted in ‘little if any effect upon levels of use', but prevalence of cannabis use ‘increased sharply' between 1992 and 1996. However, rates increased equally rapidly over this period in countries with rigorous prohibition, and prevalence and street price of cannabis is currently similar in Holland and the United States. But there is some evidence that the Dutch have been succesful in separating ‘hard' and ‘soft' drugs; only 22 per cent of Dutch cannabis smokers have tried cocaine compared with 33 per cent in the United States. The conclusion is that depenalization did not significantly increase consumption, a finding which has been replicated in several states of the United States, Italy, and Spain. Decriminalization of cannabis in Canberra, Australia, had no impact on prevalence of use among university students. (3) Very few abstaining students would start smoking cannabis if it was legalized. (4) The Dutch surge in prevalence after 1983 is probably explained by increased promotion and commercialization.

Who uses drugs and why?

Recreational drug use is a worldwide phenomenon with considerable national and regional variations. In 1995, 28 per cent of British men and 26 per cent of women admitted to being regular cigarette smokers. The decline in smoking by adults in the developed world has not been mirrored in children, and in particular the rate of initiation among girls under 16 has doubled over the last two decades in the United Kingdom. By the age of 16 years, 94 per cent of young people have tried alcohol, and 78 per cent will have been drunk on at least one occasion.

Sixteen-year-olds from the United States and the United Kingdom topped the league in lifetime experience of any illicit drug in a comparison of 23 countries. (5) Forty-one per cent of British school students admitted using cannabis in comparison with 34 per cent of North American, 19 per cent of Italian, 15 per cent of Spanish, 12 per cent of French, and 2 per cent of Greek students. Overall, around one in four of the British population have tried an illegal drug at some time. Peak use occurs in the late teens and early twenties. Cannabis accounts for 85 per cent of this and most cannabis smokers never use any other illegal drug.

Polydrug use is the norm on the club scene. Among a sample of Scottish clubbers, (6) individuals had consumed a lifetime average of 11 different drugs. Drug use within the past year included alcohol (96 per cent), cannabis (96 per cent), ecstasy (87 per cent), tobacco (86 per cent), LSD (79 per cent), amphetamine (77 per cent), cocaine (59 per cent), ‘poppers' (51 per cent), psylocybin mushrooms (47 per cent), temazepam (39 per cent), diazepam (26 per cent), codeine (19 per cent), heroin (11 per cent), ketamine (7 per cent), solvents (6 per cent), and buprenorphine (6 per cent). Other studies confirm that use of LSD, amphetamine, ecstasy, magic mushrooms, and poppers cluster together among young people. A quarter of all 18-year-olds have tried two or more illegal drugs. (7) In a consecutive sample of 100 patients attending an Oxford drug dependency unit, 22 per cent were regularly using three or more street drugs apart from heroin at presentation (unpublished data).

Only 3 per cent of the drug-using population ever injects, but those who do expose themselves to greatly increased risks of accidental overdose, poisoning by adulterants and impurities, and life-threatening infections. Superficial veins progressively thrombose, necessitating recourse to the larger vessels in the neck or groin where damage to an adjacent artery or nerve may threaten life or limb. A sizeable minority persist in exposing themselves to the risk of hepatitis and HIV through the sharing of equipment, and this is particularly prevalent among younger injectors.

Why take drugs? Some have argued that the search for ‘altered consciousness' is a basic human appetite, (1,8) but most young experimenters would simply say that drugs are pleasurable, exciting, or useful for getting into the party spirit. Other reasons include the relief of unpleasant feelings such as shyness or anxiety, fitting in with friends, or revelling in a sense of sophistication, rebellion, or independence. (4) Males are less likely to be total abstainers and tend to consume larger quantities than females. Genetic make-up, psychological factors, family background, and socio-economic circumstances are all influential in shaping the response to an offer of a drug and in determining the cost–benefit equation that will result in cessation, persistance, or abuse. (9)

Risk-taking is an essential part of the process of developing independence and individual identity during the progression through adolescence into adulthood. Because drugs are now part of the environment for most school students, it can no longer be assumed that experimentation is necessarily pathological or abnormal. In a prospective study (10) of 100 American children followed from the age of 3 to 18 years, the subjects broadly fell into three categories with regard to illicit drug use at the end of the investigation: total abstainers, experimenters, or regular users. Those with the healthiest psychological profiles proved to be the experimenters, who had also been in receipt of a significantly higher quality of parenting than either of the other two groups. Psychological traits detectable in the earliest years can predict future drug use, and the triad of alienation, impulsivity, and distress usually precedes abuse. The authors concluded that problem drug use was more likely to be a symptom, rather than a cause, of personal or social maladjustment.

Consequences of drug use for young people

Adverse outcomes can be immediate or deferred. Any form of intoxication carries the risk of accidents and other consequences of impaired judgement or self-concern. The impact of alcohol is terrifying: 1000 British people are killed and more than 20 000 hospitalized by drunk drivers each year; half the reported violent attacks upon strangers and acquaintances, and a third of all domestic violence is perpetrated by people who are drunk at the time. (7) The immediate risks of street drugs are largely related to the low priority to which criminals ascribe to quality control. Variable purity means that accidental overdose is always possible, street drugs often contain toxic by-products, bulking agents, or adulterants, and organic material may be contaminated with pesticides, fungi, or bacteria. The psychological impact of stimulants or hallucinogens can be overwhelming, and young people are at risk from the lifestyle consequences of the street drug scene such as violence or sexual exploitation. In the United States alone more than half a million unborn babies are exposed to illicit drugs each year. Families can be split apart, education disrupted, and careers terminated.

However, most legal and illegal drug users escape such acute disasters, and there is an enormous discrepancy between the large numbers revealed through population surveys to have experimented with various drugs and those who go on to develop problems with them later in life. Prospective studies (11,12,13,14 and 15) also suggest that modest controlled consumption rarely produces measurable long-term damage. Some people are able to use ‘hard' drugs such as heroin, cocaine, and amphetamine in a controlled way, and differ significantly in their personal characteristics and patterns of use from those who surface in clinics or police cells as a result of legal, medical, or social problems. (16)

On the other hand, an early onset of legal or illegal drug use, or regular heavy consumption during the teenage years, is certainly associated with a detrimental impact on mental or physical health later in life, difficult family, social, and sexual relationships, and disrupted education and employment. Such ‘problem drug use' is likely to overlap with other undesirable behaviours such as delinquency, teenage pregnancy, and school drop-out, and probably shares many causative factors. Approximately 10 per cent of experimenters with alcohol or drugs will go on to develop problems with them at some time, and vulnerability factors include physiological attributes related to genetics and neurochemical balance, certain personality traits, attitudes, and mood states, parental attitudes and behaviour, peer influences, quality of schooling, socio-economic circumstances, and availability and cost of drugs. (17)

In those who become dependent a chaotic lifestyle will greatly aggravate the damage, particularly if the intravenous route is adopted. Long-term follow-up suggests that opiate dependence is usually a chronic relapsing and remitting condition with a mortality rate of 10 to 15 per cent over 10 years. On the other hand, up to half the subjects will be abstinent from opiates by the end of this period. The relatively benign prognosis in those who survive supports a harm-reduction approach aimed at minimizing day-to-day risks. There is no comparable research that could provide information about outcome for polydrug users or people dependent upon drugs other than opiates.

Drug and alcohol abuse among the seriously mentally ill is associated with greater consumption of inpatient care and poorer compliance with treatment. (18) The prevalence of violence is higher than in severe mental illness alone. (19) In the United States, specialized services for ‘dual-diagnosis' patients have evolved and appear more effective than general psychiatric units. (20)

Do school prevention programmes work?

Outcome research of prevention programmes in the United States has been the subject of a comprehensive review. (21) Programmes should be guided by awareness that the average age of trying alcohol, cigarettes, solvents, or cannabis for the first time is between 11 and 13 years, and that exposure to drugs is now the norm for older teenagers. (22) The two distinct aims are to delay experimentation in younger children and to minimize harm in those over 13, many of whom can be assumed to be dabbling already or to have friends who are doing so. Only those programmes that actively involve students in discussion and debate, and provide relevant skills training such as assertiveness, ways of resisting social pressure, problem solving, stress management, and confidence boosting, have any measurable benefit. Improvement in knowledge without this practical dimension has no effect on behaviour, and scaremongering or moralizing can be actively counterproductive.

Because the large majority of well-integrated children with good familial support are unlikely to sustain long-term damage from transient experimentation, there is a growing awareness of the need to target vulnerable children before serious involvement with drugs or other self-destructive behaviours has been established. A prevention strategy that does not address the social and economic conditions that foster compulsive drug use and ruthless black-marketeering is just tinkering round the margins of the real problem.

What is meant by the harm-reduction approach?

In the early 1980s, a radical departure from the conventional abstinence-oriented approach took place when it was appreciated that ‘the spread of HIV is a greater danger to individual and public health than drug misuse'. (23) A harm-reduction philosophy is centred on the belief that it is possible to exert a powerful impact upon morbidity and mortality without necessarily insisting upon abstinence. A hierarchy of aims begins with attempts to make contact with as many problem drug users as possible in order to provide access to clean needles and syringes, advice about safer sex and injecting, basic health care, and help with housing, child care, or legal issues. Then, for some people but not all, a move away from street drugs on to a prescribed oral substitute may be feasible, possibly followed by detoxification and rehabilitation.

Whether through success of this strategy or just good fortune, a serious HIV epidemic among injectors similar to that experienced in the United States and some European countries has not materialized in the United Kingdom. Unfortunately, the same cannot be said about hepatitis C, which is becoming rampant. 


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