Illegal Drug Use

Predicting Addiction: Breaking the burden of illegal drug use

The impact of illegal drug use affects all of us directly or indirectly, either in human or economic terms. The huge cost of addiction makes its causes, treatment and prevention hot topics worldwide. The debate and ethical dilemmas around why some people become involved with substance abuse, and what to do after they have, are complex and controversial.

For 20 years, Professor Wayne Hall has worked in this compelling field, looking at addiction from the perspective of both the individual and society. His research has worked to uncover the real size of the burden of addiction in communities and he has addressed socially important and intellectually challenging scientific and policy questions at the intersection between drugs, human biology and history.

According to Hall, understanding addiction means unravelling our historical relationship with drugs. “Human beings have used substances derived from plants (alcohol, cannabis, cocaine, nicotine, opioids, and many others) to alter their mood and thinking for thousands of years,” he says. “For much of this time, these substances were only available in forms that delivered mild doses at certain times of year and this greatly limited the amount and frequency of drug use. Industrialisation, however, enabled humans to mass produce the active principles of these drugs in more concentrated forms – gin, cocaine and heroin – and to develop more efficient methods of administrating them, such as hypodermic syringes and tobacco cigarettes. These developments enabled modern humans to use greater quantities of these drugs much more often. Some users become addicted – that is, become regular users who find it difficult to control or stop using drugs despite the adverse affects on their health. The recognition of the phenomenon of alcohol and drug addiction has only slowly developed over the past two centuries.”

Through his research, Hall has been able to make a number of contributions to knowledge about addiction. One of these has been to improve our understanding of the adverse health effects of cannabis, particularly its role in serious mental illnesses such as psychosis. Another is the development of dependence and the effects of early and regular use on adolescent development, a topic on which he gave evidence to the House of Lords in the UK. “Those who use cannabis more often than weekly in adolescence are more likely to develop dependence, use other illicit drugs, and develop psychotic symptoms and psychosis,” says Hall. “Regular users of cannabis are more likely to use heroin, cocaine, or other drugs, but the reasons for this remain unclear.”

Another of Hall’s contributions has been to improve policy responses to heroin dependence. “Our work on the epidemiology of fatal and non-fatal overdose deaths from heroin helped to make these deaths a public health policy priority,” he says. This prompted police services to develop protocols to reduce police attendance at non-fatal overdoses to reduce users’ fears about calling for ambulances. It also led to the development of user education to
avoid risky injecting practices and it contributed to the Federal Government’s $600M ‘Tough on Drugs’ initiative. “There was a 40% decline in opioid overdose deaths in 2001 that has been sustained since, although argument continues about what specific policy interventions were responsible for producing this decline,” says Hall.

This work has appeared as a widely read book on the treatment of heroin dependence and a highly cited article in The Lancet. In this strongly contested policy area, Hall’s reputation for fair and even-handed analysis of research led to him serving as a member of the World Health Organization (WHO) Expert Committee on Drug Dependence and participating in evaluations of the Swiss heroin trials. Hall’s research has helped to improve understanding of the harm illicit drug use causes in Australia and around the world and has led to the development of the Illicit Drug Reporting System, which monitors trends in illicit drug use in Australia. “I also collaborated in research on opioid overdose, which showed that opioid overdoses, fatal and non-fatal, were far more common than first thought but also potentially preventable,” he says. “Additionally, I helped the WHO revise estimates of the contribution that illicit drug use makes to the global burden of disease.”

At the end of 2001, feeling in need of a new challenge, Hall moved to the University of Queensland to work on the public policy and ethics of new biotechnologies arising from the sequencing of the human genome. He still worked on addiction, among other topics, but from the new perspective of human genetics. This later broadened to include an interest in researching addiction and the brain, because it became clear that this was a rapidly developing field that promised to provide important insights into how addiction develops from the chronic use of alcohol, nicotine and illicit drugs.

This work has focused on the following questions: how might neuroscience change the way we think about and treat addiction and those that suffer from it; and what might be the impact of new technologies, such as drug implants, neuroimaging, and brain stimulation in treating and preventing addiction? In 2002 Hall wrote one of the first reviews of this field for the WHO and in 2008 led a similar review for the Australian Ministerial Council on Drug Strategy.

Among the questions that have been considered are:

• What are the potential uses that can be made of evidence that there is a genetic basis for the likelihood of developing nicotine dependence?
• Should we consider screening the entire Australian population for genetic susceptibility to addiction?
• Should we use genetic information to match smokers to treatments that give them the best chance of quitting?

This article was originally published in Australian Health and Medical Research – Working to Build a Healthy Australia.