First Time Cannabis Use and Sexual Debut in U.S. High School Adolescents.

PURPOSE: Use of illicit drugs by adolescents might facilitate or trigger other risky behaviors, including early sexual initiation (ESI), multiple partners, and unprotected sex. This study examines whether the age at which adolescents initiate cannabis use is associated with the age of their first sexual intercourse in the U.S. in 2015.

METHODS: A secondary analysis of data from the 2015 Youth Risk Behavior Surveillance Survey, a cross-sectional, nationally representative survey, was conducted (n = 7,664). Exposure of interest was age of initiation of cannabis use (never used cannabis, age 12 or younger, 13-14 years of age, and age 15 or older) and outcome was ESI (14 years old or younger). Unadjusted and adjusted odds ratios (OR) and their 95% confidence intervals were computed.

RESULTS: Prevalence of ESI was 15.3%. The proportion of cannabis use was 39.9%. Adolescents starting cannabis use before the age of 15 had higher adjusted odds of ESI (OR ranged 4.2-6.7). This association is modified by sex: while in boys using cannabis before 13 years, the OR is 9 (95% CI 5.2-15.6); in girls, it is 2.8 (95% CI 1.7-4.7).

CONCLUSIONS: Our findings suggest that there should be sex and drug education programs instituted before the age of 12 ideally, and no later than by age 15 since this time represents a critical period of initiating both behaviors.