Risk perceptions predicted subsequent vaccination. However, perceived risk phrased in terms of feelings rather than as a purely cognitive probability judgment predicted better. Because neither feeling at risk nor anticipated regret is represented in the most commonly used theories of health behavior, the data suggest that these theories are missing important constructs.

No abstract

Adolescents involved with the juvenile justice system have a high incidence of risky sexual behaviors resulting in unintended pregnancy and sexually transmitted infections. Substance use may be particularly important as a risk factor for unsafe sexual behavior for this group, and recent evidence suggests a possible association between marijuana use and risky sexual behavior. Adolescents (n = 728; 33% female) on probation were followed for 2 years, at intervals of 6 months, to explore the association of marijuana use and condom use longitudinally and at a specific intercourse occasion. Latent growth curve modeling indicated that greater marijuana use at baseline was associated with a steeper decline in condom use over the 2-year period of the study. In-depth analysis of the most recent intercourse occasion suggested that condom use was less likely if marijuana was being used by the participant or his/her partner and that this association was more pronounced if intercourse occurred with someone the participant had just met. Implications for the prevention of risky sexual behavior in this population are discussed.

Multiple studies suggest an association of marijuana use with increased rates of sexual risk behavior and sexually transmitted diseases (STDs). Most studies have focused on global associations of marijuana use with sexual risk outcomes and few have examined relevant cognitive variables. Adolescents in the juvenile justice system are at elevated risk for HIV/STDs and preliminary evidence suggests that marijuana is a potentially important cofactor for sexual risk behavior in this population. This study evaluated global, situational and event-level associations of marijuana use and sex-related marijuana expectancies with sexual risk outcomes in a large, racially diverse sample of adjudicated youth (n = 656, 66% male, mean age = 16.7 years). Cross-sectional and prospective analyses identified associations of marijuana use and dependence symptoms with sexual risk outcomes, including lower frequency of condom use and higher STD incidence. Stronger sex-related marijuana expectancies predicted greater intentions for and frequency of marijuana use in sexual situations. In event-level analyses that controlled for alcohol, marijuana use predicted a significantly decreased likelihood of condom use; this association was moderated by sex-related marijuana expectancies. Mediation analyses suggested that behavioral intentions partly accounted for the prospective association of expectancies with marijuana use before sex. These results provide further evidence that marijuana use is a potentially important cofactor for HIV/STD transmission in high-risk adolescents and suggest that cognitive factors could be important for characterizing this association.