How Multiple Sex Partners Shows Teen Risky Behavior

It is not unusual for teens to date multiple people during their adolescence. Some may even have sex. According to the 2019 Youth Risk Behavior Surveillance (YRBS) study, 27.4% of high schoolers are sexually active (meaning they had sex within the three months prior to the study).

However, having sex with multiple partners in a short period of time is a much rarer behavior. In the 2019 YRBS study, only 20.5% of sexually active teens (roughly 5% of high schoolers overall) reported having sex with two or more people during the previous three months.

It probably comes as no surprise that teenagers and young adults who have multiple sexual partners are significantly more likely to have substance abuse problems than those who limit their sexual activity.

Substance Abuse and Other Risky Behaviors

A 2011 study looked at the associations between the number of lifetime sexual partners and level of substance use among high schoolers. Compared to teenagers who had never had sex, teens who'd had sex with multiple people were much more likely to use alcohol, cigarettes, and marijuana. Within the analysis, the number of sexual partners went up in a step-wise fashion as the intensity of substance abuse increased.

These trends were much stronger for females than males. A girl who'd had six or more sexual partners in her lifetime was up to 40 times more likely to report heavy alcohol use than a girl who'd never had sex. Meanwhile, boys who'd had six or more partners were only 20 times more likely to develop heavy alcohol use.

In addition to substance abuse, having sexual intercourse with multiple partners increases the risk of unintended pregnancy, sexually transmitted diseases, and resulting damage to reproductive health.

Girls (but not boys) with multiple sexual partners are also more likely to have condomless sex, another dangerous behavior that compounds the risks of sex with many partners.

Does Drinking Prompt Multiple Partners?

There is some disagreement among researchers about whether having multiple sexual partners is a factor in the later development of substance abuse disorders or if the substance abuse increases the likelihood of having sex with multiple partners.

Some studies have shown that with frequent and heavy drinking, there is a greater likelihood of risk-taking, including having multiple sex partners.

One study of 533 ninth graders across a 13-year period found that alcohol use "was a leading indicator of changes in a number of sex partners throughout adolescence." But, the reverse pattern was not found—having multiple sexual partners was not linked to increased alcohol use.

No Link to Depression or Anxiety

However, a longitudinal New Zealand study examined the relationship between number of sex partners over three age periods (18–20, 21–25, and 26–32 years) and diagnoses of anxiety, depression, and substance dependence disorder at 21, 26, and 32 years.

The results showed that the higher an individual's average number of sexual partners each year, the greater their likelihood of developing a substance dependence disorder later on. This trend was especially strong for women.

Why Is Sex Linked with Substance Abuse?

Researchers have speculated on the reason that having multiple sexual partners might be linked to developing later substance abuse problems. Here are some of the possibilities:

• Sexual risk-taking and substance abuse are common risk-taking behaviors in adolescence and young adulthood.
• Occasions of substance abuse are opportunities for sexual behavior due to disinhibition and lowered perception of risk.
• People are more likely to meet new sexual partners in situations in which alcohol is served, and alcohol may facilitate multiple partnering.
• Something about having multiple sex partners puts people at risk of substance abuse disorders.

Researchers speculate that it might be the perceived impersonal nature of multiple partner relationships that prompts later substance abuse. Or, they say, perhaps having multiple failed relationships creates an attitude in which substance abuse is likely.