A/HRC/32/32 VI. Adolescents, substance use and drug control A. Nature of and problems associated with substance use in adolescence 95. Adolescence is a period of risk-taking and experimentation with greater likelihood of initiation into substance use. Adolescents are at higher risk of drug-related health harms, while substance use initiated in adolescence can more often lead to dependence than during adulthood. The most commonly used substances are alcohol, tobacco and solvents. Illicit drug use, in particular cannabis, is also common and in recent years unregulated novel psychoactive substances have become an important concern. 78 96. Outside of high-income countries, data relating to adolescent substance use and related health harms are poor. Important differences exist among and within countries, between adolescents and their older counterparts and among groups of adolescents. For example, heavy episodic or binge use, especally of alcohol, is more common among young people.79 Adolescents’ access to services is limited in comparison to adults, for example, being under the legal age of majority can block adolescents from accessing certain services. Those identified at greatest risk of drug-related harms are those who are street-involved, excluded from school, have histories of trauma, family breakdown or abuse, and those living in families coping with drug dependence. Adolescent girls are at a higher risk of certain kinds of harm than boys, including HIV infection due to both sexual transmission and unsafe injecting practices. These factors demand concerted efforts to gather appropriately disaggregated data to better understand patterns of vulnerability so that services can be targeted and properly budgeted. 97. In addition to substance use, there are significant physical and mental health consequences to adolescents’ involvement in the production of and trade in substances. Adolescents are involved at all stages of the licit and illicit drug supply chains. With regard to illicit drugs, in addition to sometimes hazardous work, adolescents can be exposed to organized crime, violence and counter-narcotics operations. More research is needed into the adolescent health implications linked to the production of drugs and the violence associated with the criminal market. 98. The harms associated with drug use and involvement in the drug trade cannot be disentangled from State responses. Evidence shows that repressive and punitive responses to drugs have not been effective in reducing drug use or supply80 and that they have produced negative consequences, including violence and corruption. 81 Criminalization of drug use and personal possession, as well as drug user registries and police violence, drive young people from services, producing a health-deterrent effect. Prevention and education programmes that focus on zero tolerance create an environment where adolescents may be less likely to seek information about harms related to use. Adolescents have lost parents to drug-related violence and to prolonged incarceration for non-violent offences, with significant implications for their mental health. 78 79 80 81 20 UNODC, World Drug Report 2015 (United Nations publication, Sales No. E.15.XI.6). WHO, Global Status Report on Alcohol and Health 2014. Louisa Degenhart and others, “Toward a global view of alcohol, tobacco, cannabis and cocaine use: findings from the WHO World Mental Health Surveys”, PLOS Medicine, vol. 5, No. 7 (2008); and European Commission, Netherlands Institute of Mental Health and Addiction and Rand Europe, A Report on Global Illicit Drugs Markets 1998-2007 (2009). E/CN.7/2008/CRP.17.