teens — On average, the students went to bed at 10:20 p.m. and got up at 7:06 a.m. during the week. Image: ktaylorg/Istock.com via AFP Relaxnews

A French study, published in the journal Scientific Reports, has linked lack of sleep and late bedtimes to a reduction in the volume of gray matter in the brains of teenagers.

Poor sleep habits in teenagers are associated with modifications in the anatomy of the maturing adolescent brain, according to researchers at the French National Institute of Health and Medical Research, INSERM, Unit 1000 “Neuroimaging & Psychiatry.”

Scientists studied the brains and the sleep habits of 177 14-year-old students in middle schools in the Paris region.

On average, the students went to bed at 10:20 p.m. and got up at 7:06 a.m. during the week, and went to bed at 11:30 p.m. and got up at 9:45 a.m. at the weekend.

The researchers found that less than seven hours of sleep during the week and late weekend bedtimes were associated with lower volumes of gray matter in certain parts of the brain.

More significantly, they found that the later teens went to bed at the weekend, the more their gray matter was diminished, according to study author and INSERM research director, Jean Luc Martinot.

These modifications affect three regions of the brain in particular: the frontal, anterior cingulate and precuneus cortex regions. These regions are associated with attention, concentration and the ability to carry out simultaneous tasks.

What’s more, tiredness from lack of sleep may not be the only cause of poorer school performance. The researchers found that poor grade averages were associated with less gray matter in frontal regions, where volume is reduced by late weekend bedtimes.

The scientists advise parents to be particularly vigilant about teenagers’ weekend sleep routines to maximize the potential for brain development and to favor academic success. JB