Late Bedtime Linked to Higher Rates of Depression and Anxiety, Large-Scale Study Finds

You relish those late nights, burning the midnight oil as a badge of honor. But that exhilarating lifestyle of staying up into the wee hours may be silently sabotaging your mental health.
A large-scale new study from Stanford Medicine suggests that no matter your chronotype, late bedtimes significantly increase the risks of depression, anxiety, and other behavioral disorders.
One factor is that nocturnal activity often breeds impulsive and maladaptive behavior, she said. The brain operates differently during nighttime wakefulness, especially in areas such as risk assessment, behavioral inhibition, and cognitive control, she said.
When people align with societal norms and more people are awake simultaneously, it can promote better mental well-being, Ms. Lok noted. Night owls, however, may experience poorer mental health due to misalignment with common sleep patterns, she said. They’re often expected to wake up early for work despite insufficient sleep, leading to grogginess, reduced performance, and adverse mental health outcomes.
Mr. Walker likens a night owl’s brain forced to wake early to a cold engine starting: It takes a long time to warm up and function efficiently.
During a typical 90-minute sleep cycle, the ratio of NREM to REM sleep changes dramatically throughout the night. The first half is dominated by deep NREM sleep, with very little REM sleep, while the balance shifts in the second half, with minimal deep NREM sleep and an abundance of REM sleep, Mr. Walker noted.
According to Mr. Walker, missing out on NREM sleep in the first half of the night impairs the process of removing and pruning unnecessary neural connections.
However, Mr. Zeitzer said that according to his team’s research, the ratio of NREM to REM sleep, as well as the depth of REM sleep, should not be affected if night owls go to sleep late.
Vigorous exercise late at night activates the sympathetic nervous system, releasing stimulating hormones and neurotransmitters that make it harder for our minds and bodies to transition into deep sleep, Dr. Rose Anne Kenny, a geriatrician, professor of medical gerontology, and author of “Age Proof,” wrote in her book.
Late-night eating can also be a contributing factor, especially when it involves foods and drinks high in tyramine, an amino acid that triggers brain alertness. Aged cheeses, wines, certain beers, and cured meats are among the culprits.
She further recommends incorporating sleep-promoting foods that enhance neuropeptides, such as tryptophan and melatonin. These include turkey, almonds, chamomile tea, fatty fish, kiwis, milk, cottage cheese, tart cherry juice, and bananas.
Deep sleep can also be enhanced through sound stimulation, such as listening to pink or white noise, Dr. Kenny said.