The polydrug pattern of drug use by pregnant women, combined with the varying purity, dosage, and timing during pregnancy when drugs are taken, makes it very difficult to determine the developmental impact of any specific drug. Nevertheless, studies of drug-exposed newborns suggest an array of behavioral characteristics that make their care challenging, and a few studies indicate that some pren...

Background.  Sexual transmission of hepatitis C virus (HCV) among human immunodeficiency virus (HIV)-infected men who have sex with men (MSM) is an emerging issue. Studies addressing the temporal trends and risk factors associated with incident HCV in HIV-infected MSM in the community-based primary care settings in the United States are scarce. Methods.  Using a retrospective cohort study desig...

PURPOSE To determine the social contexts associated with the past-year substance use (multiple substances, alcohol, marijuana, and nonmedical use of prescription opioids, stimulants, and tranquilizers) among U.S. high school seniors. METHODS A secondary analysis of nationally representative survey data from 10 cohorts (2002-2011) of the Monitoring the Future study, including 24,809 high schoo...

BACKGROUND Opioids can impair psychomotor performance, and driving under the influence of opioids is associated with an increased risk of accidents. The goals of this study were i) to determine the prevalence of opioids (heroin, morphine, codeine, methadone and tramadol) in Spanish drivers and ii) to explore the presence of opioids, more specifically whether they are used alone or in combinatio...