Substance dependence treatable, says neuroscience expert report: psychosocial, environmental, biological and genetic factors all play significant roles in dependence, says new report published by WHO.

18 March 2004 | GENEVA/BRASILIA-The World Health Organization (WHO) today launched Neuroscience of Psychoactive Substance Use and Dependence, an authoritative report summarizing the latest scientific knowledge on the role of the brain in substance dependence. The report* is the first of its kind produced by WHO, and cites an explosion of advances in neuroscience to conclude that substance dependence is as much a disorder of the brain as any other neurological or psychiatric disorder. Substance dependence is multifactorial, determined by biological and genetic factors, in which heritable traits can play a strong part, as well as psychosocial, cultural and environmental factors, says the report. It has been known for a long time that the brain contains dozens of different types of receptors and chemical messengers or neurotransmitters. The report summarizes new knowledge on how psychoactive substances are able to mimic the effects of the naturally occurring or endogenous neurotransmitters, and interfere with normal brain functioning by altering the storage, release and removal of neurotransmitters. The report discusses new developments in neuroscience research with respect to craving, compulsive use, tolerance and the concept of dependence. The report shows that psychoactive substances have different ways of acting on the brain, though they share similarities in the way they affect important regions of the brain involved in motivation and emotions. The report discusses how genes interact with environmental factors to sustain psychoactive substance-using behaviours. This knowledge is the basis of novel diagnostic tools and behavioural and pharmacological treatments. The report urges increasing awareness of the complex nature of these problems and the biological processes underlying drug dependence. It also supports effective policies, prevention and treatment approaches and the development of interventions that do not stigmatize patients, are community based and cost-effective. "The health and social problems associated with use of and dependence on tobacco, alcohol and illicit substances require greater attention by the public health community and appropriate policy responses are needed to address these problems in different societies," says WHO Director-General Dr LEE Jong-wook. "Many gaps remain to be filled, but this important report shows that we already know a great deal about the nature of these problems." United Nations Office on Drugs and Crime (UNODC) data estimates about 205 million people make use of one type of illicit substance or another. The most common is cannabis, followed by amphetamines, cocaine