Multiple Sex Partners Increase Risk of Alcohol or Marijuana Dependence

A new study links the number of sex partners young adults have with their subsequent risk of developing alcohol or marijuana dependence disorders. The study found young women who had more than two or three sex partners when they were 18 to 20 years old were nearly 10 times more likely than those with one or no sexual partner to develop a substance dependence problem at age 21.

Time.com reports researchers at the University of Otago in New Zealand found the risk of developing substance dependence disorders increased, the more sexual partners a person had. Having more than two or three partners from age 21 to 25 raised the risk of addiction at age 26 sevenfold. At age 32, women had a nearly 18 times greater risk if they had two or three partners when they were 26 to 31, compared with their peers with one or no sexual partner during that period.

Men’s risk also increased, but not as dramatically. Men who had one sex partner from age 18 to 20 had nearly three times the risk of a serious substance use disorder at age 21. Having more than two or three partners increased their risk fourfold.

The findings appear in the Archives of Sexual Behavior.

The researchers said multiple sex partners and later substance abuse could be linked because they are part of a cluster of risk-taking behaviors that happens in adolescence and young adulthood. Alcohol and marijuana use may encourage sexual behavior, they added.

Study lead author Dr. Sandhya Ramrakha noted in a news release that pubs and bars are places where one can easily meet partners. “The role of the alcohol industry in encouraging the view that alcohol is entertainment, targeting young women in particular, is disturbing. Young women are also encouraged to ‘keep up’ with young men in relation to their drinking,” Dr. Ramrakha noted.