According to the results of a new research study carried out by researchers from Pennsylvania State University, teenagers are more likely to have consumed alcohol or tried cannabis by the age of 15 years if they went to bed later and slept fewer hours during childhood and adolescence. The study, published in the peer-reviewed journal Annals of Epidemiology, analyzed data collected from 1,514 children as part of the Future of Families and Child Wellbeing Study, a longitudinal study including children from 20 cities across the United States. As part of the study, the parents reported their child’s weekday bedtime at ages three, five and nine. Moreover, they reported their child’s sleep duration at the ages of five and nine.

The researchers focused on examining the total duration of sleep and time of sleep or bedtime, noting that going to bed later could affect children’s ability to sleep well. It was found that adolescents were 45% more likely to try alcohol by the age of 15 years if they had a later bedtime at age nine when compared to children with earlier bedtime at age nine. 

However, bedtime at age five wasn’t associated with future alcohol use, and neither was sleep duration at ages five or nine. In addition, it was found that later bedtime at age five was associated with 26% increased odds of trying cannabis by the age of 15 years, while sleeping an hour less at age nine was associated with 19% increased odds of trying marijuana by the age of 15.

Furthermore, researchers also analyzed data collected from adolescents at the age of 15 years, who self-reported their bedtime, sleep duration, and alcohol and cannabis use. It was found that teens with a later bedtime had a 39% increase in the likelihood of drinking alcohol and a 34% increase in likelihood of trying cannabis. Sleeping one hour less was associated with a 28% increase in the likelihood of trying alcohol, but was not significantly associated with cannabis use.

“Sleep at ages closer to adolescence is the most crucial in terms of future substance use risk. It’s that stage of development when children are rapidly changing and their brain is maturing,” said Dr. David Reichenberger, the study’s co-lead author, in a press release. In addition, he noted that previous research has already shown that shorter sleep duration and later bedtimes are linked to increased impulsivity and may negatively impact decision making, potentially influencing substance use choices.

“Exploring the connection between sleep and substance use is a critical area of research because we continue to struggle with an epidemic of opioid addiction and substance use,” said Dr. Anne-Marie Chang, associate professor of biobehavioral health at Penn State and senior author of the paper in a press release. “It’s an important area to continue to research and to disseminate our research findings to the broader population, families and health care professionals.”