The section you quoted was about questions they asked the students: How lonely did they feel, how often did they drink alcohol.
Gather 580 middle school students and you’ll find a subset of them engaging in shocking behavior. This can usually be traced back to a combination of disengaged parents and older siblings who are a bad influence. 13 year olds are teenagers and are plenty capable of stealing their parents’ alcohol if desired.
The prevalence of these behaviors varies wildly from one demographic to another. I’ve been involved with schools with highly involved parents where a student even hearing rumors of one of their peers consuming alcohol would set in motion a chain of events where parents talked to each other and their kids about alcohol use and took steps to keep each other informed and lock their own alcohol away.
Meanwhile I have extended family who teach in two different farming communities. It’s not uncommon for even middle schoolers to get caught with drugs or arrive at school under the influence of something. Not all of them, of course, but it’s a frequent enough occurrence that it’s not all that noteworthy when it happens again.
The range of parenting styles and home environments across the United States is extreme. It can be unfamiliar to many who grew up in one bubble to hear about the vast differences that exist in other bubbles.