About 75% of the men and at least 55% of the women involved in acquaintance rapes had been drinking or taking drugs just before the attack.
Source: Robin Warshaw. 1994. I Never Called It Rape: The Ms. Report on Recognizing, Fighting and Surviving Date and Acquaintance Rape. New York: HarperPerennial.

Teens 14 and younger who use alcohol are twice as likely to have sex than those who don't.

Teens 14 and younger who use drugs are four times likelier to have sex than those who don't.

Teens 15 and older who drink are seven times likelier to have sexual intercourse and twice as likely to have it with four or more partners than non-drinking teens.

Teens 15 and older who use drugs are five times likelier to have sexual intercourse and three times likelier to have it with four or more partners than those who don't.

63% of teens who use alcohol and 70% of teens who are frequent drinkers have had sex, compared to 26% of those who never drank.

72% of teens who use drugs and 81% of those who use them heavily have had sex, compared to 36% who never used drugs.
The National Center on Addiction and Substance Abuse at Columbia University (CASA)