Studying Youth in Northern California (SYNC) is a public health research study assessing narcotic and stimulant use among 14-25 year-olds in five Northern California counties with an emphasis on how such factors and forces place this population at risk for HIV and related health problems. The SYNC Study is a multidisciplinary collaboration of researchers and public health experts from SFSU, UCSF, & the counties of Alameda, Contra Costa, San Francisco, San Joaquin and San Mateo funded by the California Department of Health Services/Office of AIDS (CDHS/OA). SYNC hopes to provide information to complement previously collected data from the Young Women’s Survey (YWS) and HEYMAN studies, which were also collaborative efforts of the CDHS/OA and CAPS. This study will help to inform future public health interventions and policy targeting youth. The SYNC Study will be conducted in two phases: A formative qualitative information gathering phase regarding drug use in youth and risk of HIV 1. An epidemiological study of the prevalence of narcotics and stimulant use in 2. youth and young adults in the 5 counties. All the information we get will be used to assist county public health agencies and organizations to improve services for the treatment and care of youth at risk, and to develop better methods of helping young people prevent drug use and disease and promote good health.