Health consequences of illegal drug use.

PURPOSE OF REVIEW The aim of this article is to review recent research on the health consequences of illegal drug use and possible risk factors, with a particular focus on prospective evidence. RECENT FINDINGS Mortality studies have revealed qualitative and quantitative changes in causes of death among heroin and injecting drug users (IDUs), probably due to increasing exposure to harm reduction programs, the introduction of highly active antiretroviral therapy (HAART), the aging of drug users, and rising concurrent use of illegal drugs and prescription drugs. For morbidity, nonfatal overdose is still one of the most important concerns; likewise the higher prevalence of hepatitis C among non-IDUs and hepatitis A, B, C coinfection. Cannabis use has been consistently reported to be associated with the emergence of psychotic symptoms, yet that seems not to be the case for anxiety and depressive disorders. Use of 3,4 methylenedioxymethamphetamine (MDMA) has been linked with short-term negative effects on cognitive performance (i.e. visual memory). A series of longitudinal studies have shown enduring unfavorable effects of prenatal cocaine and marijuana exposure on children's physical, cognitive, and language development. SUMMARY Prospective evidence on illegal drug use in particular subpopulations may be needed to better understand health problems among users at different life stages and the possible long-term effects.