Adolescent Safer Sex Social Network Intervention

Inclusion Criteria: Index Participant Inclusion Criteria Self-identifies as all or part "Latino" Age is between 16 years and 0 days and 19 years and 364 days at the time of study enrollment In the past 3 months, reports engaging in any type of heterosexual sex (vaginal, oral or anal) with an opposite-sex partner In the past 3 months, reports any of the following: alcohol use at least once; marijuana use at least once; having sex while drunk or high. Must understand spoken and written English sufficiently to provide consent/assent and be interviewed and attend intervention workshops delivered in English Must live in the Boston or Tampa area, and plan to be available for study appointments (vacation allowed if not interfering with the planned intervention or follow up dates) Network Participant Inclusion Criteria Age is between 16 years and 0 days to 19 years and 364 days at the time of study enrollment In the past 3 months, reports engaging in any type of heterosexual sex (vaginal, oral or anal) with an opposite-sex partner Must understand spoken and written English sufficiently to provide consent/assent and be interviewed and attend intervention workshops delivered in English Must live in the Boston or Tampa area, and plan to be available for study appointments (vacation allowed if not interfering with the planned intervention or follow up dates) Must be reported by an index as a friend who: has been known for at least 6 months; hangs out with, or is in contact with the index at least 2 times per week; has engaged in alcohol or marijuana use with the index during the last 3 months; and gave directive guidance (gave index information on how to do something) AND, had intimate interaction (i.e. listened to private feelings of index) AND, had positive social interaction with the index. Exclusion Criteria: Index Participant Exclusion Criteria Reports only same sex behavior Reports being HIV positive, as measured by self-report Reports having engaged in behaviors in the past year that are defined as "severe" physical abuse of others on the Conflict Tactics Scale In the past year, reports having made someone engage in sexual things that he or she did not want to do either by holding the partner down, hurting or by threatening them in some way Unable to nominate at least one eligible friend to participate in the intervention Reports having ever used heroin, crack, cocaine, or metamphetamines Reports alcohol dependence as measured by affirmative answers to 3 or more out of 7 questions on the Diagnostic and Statistical Manual of Mental Disorders - 4th Edition (DSM-IV) based criteria of substance dependence Reports marijuana dependence as measured by affirmative answers to 3 or more out of 7 questions on the DSM-IV based criteria of substance dependence Reports being an active member of a gang Reports or is known by staff to be currently participating in any other bio-medical or Adolescent Trial Network (ATN)-related intervention study or trial If female, reports being currently pregnant Unwilling to be screened for sexually transmitted infections (STIs) Prior participation in this study intervention as either an index or a network member as determined by review of study logs Network Participant Exclusion Criteria Is currently romantically involved with the index who named him/her Has ever had vaginal, oral or anal sex with the index Reports only same sex behavior Reports being HIV positive, as measured by self-report Reports having engaged in behaviors in the past year that are defined as "severe" physical abuse of others on the Conflict Tactics Scale In the past year, reports having made someone engage in sexual things that he or she did not want to do either by holding the partner down, hurting or by threatening him/her in some way Reports having ever used heroin, crack, cocaine, or metamphetamines Reports alcohol dependence as measured by affirmative answers to 3 or more out of 7 questions on the DSM-IV based criteria of substance dependence Reports marijuana dependence as measured by affirmative answers to 3 or more out of 7 questions on the DSM-IV based criteria of substance dependence Self-reports being an active member of a gang Reports or is known by staff to be currently participating in any other bio-medical or ATN-related intervention study or trial If female, reports being currently pregnant Unwilling to be screened for STIs Prior participation in this study intervention as either an index or a network participant as determined by review of study logs