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Psychoactive Drugs Tobacco, Alcohol, and Illicit Substances

6. How can addiction to psychoactive drugs be prevented and treated?

  • 6.1 What are the different approaches to treating drug addiction with medications?
  • 6.2 What are the different behavioural therapies for treating drug addiction?
  • 6.3 What ethical issues are raised by research on drug addiction?

The source document for this Digest states:

Research in neuroscience has led to the development of a number of pharmacological and behavioural interventions for the treatment of substance dependence. Many have been very successful, while some remain controversial for ethical reasons. New treatments are on the horizon, and with more research, improved treatments are likely. The combination of pharmacological and behavioural therapies appears to be the most effective in treating dependence. One question that arises concerns the measures of success: is a treatment considered successful only if complete abstinence is obtained? Or, is a reduction in the amount, frequency or harmful use of a substance sufficient as a measure of success? Current pharmacological therapies are presented in Table 5.

Source & ©: WHO  Neuroscience of psychoactive substance use and dependence, Summary (2004),
Treatment and prevention: links with neuroscience, and ethical issues, p.26

6.1 What are the different approaches to treating drug addiction with medications?

The source document for this Digest states:

There are a variety of pharmacological and behavioural treatments available with proven efficacy. In terms of pharmacological interventions, one choice is of substances or procedures that interfere in one way or another with the action of the substance in the body, taking away the positive rewards from using the substance or making its use aversive. For example, the opioid receptor blockers naloxone and naltrexone, reduce the rewarding effects of opioids and alcohol (See Table 5).

Table 5. Pharmacological treatments for substance dependence

Another example is disulfiram, which interferes with the metabolism of alcohol, making its consumption aversive. However, these medications are effective only insofar as people take them. Extensive experience suggests that the main problem with such substances is patient compliance: that those with a history of extensive use of a substance are often unable to keep a commitment to continual use of the pharmacological therapy.

The other choice for pharmacological treatment options is of substances that mimic the effects of the psychoactive substance in some ways, without some of the more harmful effects of that substance. This is referred to as substitution treatment, or maintenance treatment. This choice has been most widely explored and used for opioids, with codeine, methadone, buprenorphine and other substances substituted for heroin or other opioids, to reduce illegal opioid use and the crime, death, and disease associated with substance dependence. Methadone and buprenorphine, the two medications most commonly used, are also prescribed on a short-term basis to detoxify those dependent on opioids. Many substance users who only detoxify, however --- no matter what method used --- lapse into heavy substance use. Substitution therapy seeks to reduce or eliminate illicit opioid use by stabilizing people for as long as is necessary to help them avoid previous patterns of substance use and associated harms, including sharing of injection equipment. The most common treatment, methadone maintenance, has been shown in hundreds of scientific studies to be effective in reducing substance-related harm without negative health consequences. Compared to illegal users of opioids, people who undergo methadone maintenance treatment spend less time in jail and in hospital, have better social integration and lower rates of HIV infection, commit fewer crimes, and live longer (71).

Substitution therapy has often been controversial, with the argument stated in ethical terms. On the one hand, it is stated to be unethical for the State or a treatment professional to contribute to the continuation of the dependence, even if on a substitute regime. On the other hand, the counter-arguments of the demonstrated reductions in harm to society (e.g. criminal activity) or the individual (e.g. HIV infection) from the substitute regime, are also ethical at their core.

With therapies that interfere with the psychoactive effects or that are aversive, the main ethical issue is the consent of the patient to the treatment, and the ethics of coerced treatment. The use of immunotherapies, such as for cocaine dependence (See Table 5), particularly to the extent that they are irreversible, would raise difficult ethical issues. The neuroscience findings that the use of psychoactive substances shares many pathways in the brain with other human activities also raises the question of what other pleasures or activities might be adversely affected by a treatment. The application of genetic modifications would raise many of the same ethical issues regarding potentially permanent changes.

Source & ©: WHO  Neuroscience of psychoactive substance use and dependence, Summary (2004),
Treatment and prevention: links with neuroscience, and ethical issues, Types of treatment, p.26-29

6.2 What are the different behavioural therapies for treating drug addiction?

The source document for this Digest states:

In addition to pharmacological treatment, behavioural therapies are employed in treating substance dependence. It is interesting to relate these therapies to the learning processes that were discussed with respect to the effects of psychoactive substances on the brain. Motivational and cognitive therapies are designed to work on the same motivational processes in the brain that are affected by psychoactive substances. These therapies try to replace the motivation to use substances with the motivation to engage in other behaviours. Note that these therapies rely on the same principles of learning and motivation that are used to describe the development of dependence. For example, contingency management uses the principles of positive reinforcement and punishment to manage behaviour. Cognitive behavioural therapies and relapse prevention help the person develop new stimulus-response associations that do not involve substance use or craving. These principles are employed in an attempt to ‘‘unlearn’’ the dependence-related behaviour and to learn more adaptive responses. Thus, similar neurobiological mechanisms are involved in the development of dependence, as are involved in learning to overcome dependence.

The information in Box 4 is a summary of types of psychotherapies and behavioural interventions (72).

Source & ©: WHO  Neuroscience of psychoactive substance use and dependence, Summary (2004),
Treatment and prevention: links with neuroscience, and ethical issues, Types of treatment, p.29-30

6.3 What ethical issues are raised by research on drug addiction?

The source document for this Digest states:

The rapid pace of change in the field of neuroscience research brings with it a host of new ethical issues in both research and treatment, which will need to be addressed. An influential set of moral principles guide the ethics of biomedical research (80, 81). These are the principles of autonomy, non-maleficence, beneficence, and justice (82).

The principle of respect for autonomy is usually taken to require informed consent to treatment or research participation, voluntariness in research participa- tion, and maintenance of confidentiality and privacy of information provided to a researcher. The principle of non-maleficence simply means, ‘‘do no harm’’, and requires researchers to minimize the risks of research participation. Positive beneficence requires us to perform actions that result in a benefit. The benefits to society of the research should outweigh its risks to participants, and the benefits to individual participants in research should exceed the risks. Distributive justice refers to the equitable distribution of the risks, as well as the benefits of research participation.

Perhaps the most urgent ethical issues arise around the issue of genetic screening, which is already on the horizon. A person identified by a genetic screen as vulnerable or at risk is potentially disadvantaged by that identification in a number of ways. In the first place, the person’s own self-esteem may be reduced. The person’s financial and status interests may be adversely affected if the identification is available to anyone else: an insurance company may refuse insurance, an employer may choose not to employ, a lover may refuse to marry. At present, in many countries, these adverse effects of such identification are not at all theoretical: for instance, insurance companies may have routine access to health records, or may require such access as a condition of applying for insurance (thus coercing consent).

Ethics and types of neuroscience research on substance dependence

There are many types of research on substance dependence, all of which have both unique and common ethical issues that will have to be dealt with. These include animal experiments, epidemiological research, human experimental studies, and clinical trials of therapies for substance dependence.

Clinical trials compare the effects of different drug or behavioural treatments, and sometimes placebos, on the substance use, health, social adjustment and well-being of persons with substance dependence (80). Clinical trials differ from experimental studies in one key respect: participants in clinical trials have some chance of benefiting from their participation in the study (80). The criteria for good clinical trials agree in requiring that a representative sample of the population at risk is recruited into such studies (80). An ethical issue of increasing significance, given the extent of pharmaceutical company funding of clinical trials, is ensuring public confidence in the results of clinical trials (83, 84). Additional policy recommendations have been made that have not so far been implemented. These include: independent monitoring of compliance with the study protocol, especially with reporting of any adverse events experienced by participants; and a requirement that investigators and the sponsors of a trial commit to publishing its results within two years of completing data collection, as a condition of the study protocol being approved by an ethics committee (85).

The outcomes of neuroscience research for the treatment of substance dependence will bring ethical issues to the fore. One such issue is ensuring equal access to treatment for all those who may need it. Economic and social costs of treating people with substance dependence with publicly subsidized substance treatment, as opposed to the criminal justice system will also be relevant (86, 87). As well, the potential use of a pharmacological treatment for substance dependence or a substance immunotherapy under legal coercion needs to be considered (88-90).

Source & ©: WHO  Neuroscience of psychoactive substance use and dependence, Summary (2004),
Treatment and prevention: links with neuroscience, and ethical issues, Ethical issues in neuroscience research on substance dependence , p.30-32

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