Abstract
OBJECTIVES: To describe trends over time in sexual behaviour, condom use, and sexually transmitted infections among female and male adolescents in the United States. METHODS: A review was carried out of published studies using data from six surveys since the 1970s on sexual behaviour and surveillance data on sexually transmitted infections. RESULTS: The proportion of adolescents who have ever had sexual intercourse increased for females and males through the 1980s and then declined for males through the 1990s. Some survey data showed that the level remained unchanged in the 1990s for adolescent females and other sources showed a decline by 2001. Condom use at first sexual intercourse and current condom use have increased over the past two decades for both male and female adolescents. Incidence rates for gonorrhoea and syphilis among adolescents declined over the 1990s and up through 2002, though new diagnoses of HIV/AIDS among adolescents remained relatively constant throughout the 1990s and into the new century. CONCLUSION: Although data sources are difficult to compare over time, trends in sexual behaviour, condom use, and sexually transmitted infections among adolescents from different data sources display generally similar directions towards declines in risk behaviours and outcomes, and increases in protective behaviours.