National Longitudinal Study of Adolescent HealthAdolescent BehaviorRisk-TakingLongitudinal StudiesSexual BehaviorUnited StatesViolenceAdolescent Health ServicesHealth BehaviorSubstance-Related DisordersAdolescent PsychologyBehavioral Risk Factor Surveillance SystemStudentsAlcohol DrinkingSchoolsHealth SurveysSmokingQuestionnairesPeer GroupPrevalenceAdolescent DevelopmentLogistic ModelsSex FactorsHealth StatusSuicide, AttemptedAge FactorsFriendsAdolescent MedicinePopulation SurveillanceJuvenile DelinquencyCross-Sectional StudiesRisk FactorsParent-Child RelationsSocioeconomic FactorsInterpersonal RelationsSexual PartnersCrime VictimsSexually Transmitted DiseasesRepublic of KoreaCoitusDepressionSelf ConceptHispanic AmericansData CollectionUnsafe SexAfrican AmericansSocial EnvironmentDietEducational StatusObesityMental HealthBody Mass IndexEuropean Continental Ancestry GroupExerciseHealth Knowledge, Attitudes, PracticeWounds and InjuriesHealth PromotionHIV InfectionsSiblingsResidence CharacteristicsRegression AnalysisSocial SupportAttitude to HealthParentingFamily CharacteristicsHomeless YouthMultivariate AnalysisPublic HealthParentsCohort StudiesInterviews as TopicSocial BehaviorMarijuana SmokingProspective StudiesBehavior, AnimalHealth EducationPregnancy in AdolescenceOdds RatioFollow-Up StudiesAgingUrban PopulationDelivery of Health CarePersonality DevelopmentCondomsHomosexuality, MaleFeeding BehaviorChild AbusePregnancyMental DisordersSocial ClassSubstance Abuse, IntravenousFamilyAggressionCourtshipHealth PolicyTime FactorsHealth Services AccessibilityHealth Status DisparitiesAlcoholismChild Behavior