241 un-paired twins who did not have a participating co-twin) aged 18-27 years, including 14.6% of African-American ancestry. Data on 2,950 (15.9% African-American) twin women who reported a lifetime history of any consensual sexual activity were included in the current report. However, as 166 of these women reported onset of rVUS prior to their first use of cannabis, they were excluded from analyses resulting in a final sample size of 2,784 twin women. Those reporting onset of rVUS prior to first cannabis use were more likely to be older and Black. They were also generally less likely engage in early-onset substance use behaviors but more frequently reported early sexual debut (Table S1).
