There is a new study that is in press in the journal Preventative Medicine on the relationships between hours of sleep and health risk behaviors in adolescent students. Let’s break it down.
What did they do? The investigators used data from the National Youth Risk Behavior Survey of over 12,000 high school students. They categorized sleep as sufficient or insufficient on the basis of whether students reported getting an average of more or less than 8 hours of sleep per school night. They used fancy stats (multivariate logistic regression) to calculate the likelihood (odds ratios) that sleep time would be associated with other self-reported health behaviors.
What did they find? More than two-thirds (68.9%) of students reported getting insufficient sleep as defined by an average of less than 8 hours on school nights. Insufficient sleep was significantly associated with a higher likelihood of (in order of likelihood) seriously considering attempting suicide, smoking cigarettes, feeling sad or hopeless, drinking alcohol, using a computer for more than 3 hours a day, smoking marijuana, being sexually active, getting into physical fights, not being physically active, and drinking soda/pop.
What do we take away? There are a number of limitations to this type of study. First, we are talking about associations or relationships and not cause and effect. It is possible that it is being depressed or drinking alcohol that leads to poor sleep and not the other way around. Second, the measures are self-reported and could be subject to a number of biases, including people being reluctant to report certain things or not having a good memory for past events. Nonetheless, this study benefits from using a large sample of high school kids and does show consistent relationships between sleep time and different types of health behaviors.
So, in the end, we can’t necessarily say that sleeping more will reduce the likelihood that an adolescent will drink or develop depression, but we can say that there is a strong cost/benefit that weighs in favor of getting good sleep. The benefits of good sleep are many and the costs of good sleep are few.