Millions of Americans affected by secondhand harm from substance use

The risks of alcohol and other drug consumption to the user are well known, but many Americans--nearly 160 million--say they've been harmed by someone else's substance use, according to a new study in the Journal of Studies on Alcohol and Drugs.

In a national survey of U.S. adults, researchers found that 34% said they'd ever suffered "secondhand harm" from someone else's alcohol use--ranging from marriage and family problems to financial fall-out to being assaulted or injured in a drunk-driving accident. Meanwhile, 14% said they'd been harmed by someone else's use of marijuana, opioids or other drugs.

In sheer numbers, that amounts to 113 million Americans who've suffered consequences from another person's drinking, and 46 million who've been hurt by others' drug use. What's more, there was plenty of "overlap" between those two groups: Of survey respondents reporting secondhand harms from alcohol, 30% said they'd also been impacted by other people's drug use.

There are more harms than people think. They affect families, relationships and communities."

William Kerr, Ph.D.,  study co-author of the Alcohol Research Group at the Public Health Institute, in Emeryville, Calif.

It makes sense that risky drinking and drug use have far-reaching consequences, but it's only in recent years that research has delved into the secondhand harms of alcohol, Kerr said. And little has been known about the secondhand effects of drug use.

The new findings are based on responses from 7,800 U.S. adults who were surveyed between September 2019 and April 2020--before, Kerr noted, the effects of the pandemic on Americans' substance use.

The survey asked people if they'd ever experienced a set of specific harms due to someone else's alcohol or drug use: physical harm, vandalized property, family problems, financial difficulties or involvement in a traffic accident. Far fewer people said they'd been harmed by others' drug use compared with alcohol use--which is likely because both drinking and alcohol use disorders are much more common than drug use and drug use disorders, Kerr said.

But, he added, there could also be additional reasons, including the limits of the survey (which asked about secondhand harms from drug use with a single question). The researchers are now conducting a new survey with more detailed questions on harms related to individual drugs.

In the meantime, the current findings highlight a major public health issue: For every person with a substance use disorder, Kerr said, many more may be harmed in some way, to some degree. That, he added, underscores the need to improve people's access to substance abuse treatment, and the importance of harm reduction efforts--such as preventing people from driving under the influence.