Burning the midnight oil might feel exhilarating, but those late-night adventures can secretly wreak havoc on your mental health. 

A 2024 study by Stanford Medicine researchers revealed that staying awake until the early morning hours is detrimental to mental health. The study, which included 75,000 adults, found that regardless of whether individuals are night owls or morning larks, everyone benefits from going to bed early. The findings showed that all chronotypes experience higher rates of behavioral and mental disorders, including depression and anxiety when they stay up late.

Senior author of the study, Jamie Zeitzer, Ph.D., a professor of psychiatry and behavioral sciences, told the Epoch Times that the results were very unexpected. He explained that they initially hypothesized that aligning one’s preferred bed timing (chronotype) with actual bed timing would benefit mental health. However, discovering that staying up late is detrimental to mental health, even for night owls, was a surprising finding and opens up new lines of inquiry.

How Late Bedtimes Impact Mental Health

Renske Lok, Ph.D., a postdoctoral scholar in psychiatry and behavioral health and the lead author of the Stanford Medicine study, told the Epoch Times that while the precise reasons why larks tend to have better mental health than owls are still unclear, they believe it is related to the timing of sleep. One factor is that nocturnal activity is often associated with impulsive and maladaptive behavior. According to Lok, the brain operates differently during nighttime wakefulness, particularly in areas such as risk assessment, behavioral inhibition, and cognitive control.

A 2022 review in Frontiers in Network Physiology explores the “Mind after Midnight” hypothesis, which suggests that significant nocturnal wakefulness leads to behavioral and cognitive dysregulation. The review discusses how day-night alterations can result in maladaptive behaviors such as substance abuse, violent crime, and suicide, and examines differences in executive functioning, reward processing, and mood during nocturnal wakefulness. It proposes that prefrontal disinhibition, altered reward processing, and attentional biases contribute to psychiatric disorders and behavioral dysregulation as part of the “Mind after Midnight” hypothesis.

Additionally, Ms. Lok says that staying up late at night alone, when most people are asleep, may negatively impact mental health. When individuals are better aligned with societal norms, more people are awake at the same time, which can contribute to better mental health. Night owls, on the other hand, may experience poor mental health due to a misalignment with the mainstream chronotype. They are often expected to wake up early for work despite not having sufficient sleep, leading to grogginess, reduced performance, and adverse mental health outcomes.

Giles Watkins, author of Positive Sleep, told the Epoch Times that many countries have work cultures geared towards a 9-to-5 schedule. Owls, who would naturally sleep later, are forced to wake earlier than they’d prefer, which understandably impacts their mental health and performance.

In his book Why We Sleep, Matthew Walker explains the state of a night owl’s brain, particularly focusing on the prefrontal cortex, which remains in a sleep-like state throughout the early morning. This part of the brain is responsible for logical reasoning, high-level thought, and emotional regulation. Walker likens the brain of a night owl forced to wake up early to a cold engine starting in the morning—it takes a long time to warm up and function efficiently.

The Roles of NREM and REM Sleep

According to a 2020 article in the Journal of Nature Human Behavior, sleep disruption is a recognized feature of all anxiety disorders. More specifically, non-rapid eye movement (NREM) slow-wave deep sleep has an anti-anxiety effect on brain networks, suggesting that NREM sleep could be used as a therapeutic target for meaningfully reducing anxiety.

Matthew Walker explains in his book that with every 90-minute sleep cycle, the ratio of NREM to REM sleep changes dramatically throughout the night. During the first half of the night, the vast majority of sleep is consumed by deep NREM sleep, with very little REM sleep. This balance shifts in the second half of the night, with minimal deep NREM sleep and an abundance of REM sleep. Walker notes that if you miss out on NREM sleep in the first half of the night, the process of removing and weeding out unnecessary neural connections will not take place.

However, Zeitzer noted that the ratio of NREM to REM sleep, as well as the depth of REM sleep, should not be impacted if night owls go to sleep late. He added that regardless of whether owls were sleeping in or not, their mental health was still affected, independent of the amount of sleep they got.

Barriers To Early-Night Sleep

The Stanford study recommends going to bed before 1 a.m. for improved mental health, though this is often easier said than done.

Dr. Rose Anne Kenny, a geriatrician, professor of medical gerontology, and author of Age Proof, explains that vigorous exercise late at night activates the sympathetic nervous system and releases stimulating hormones and neurotransmitters, making it harder for our minds and bodies to transition to deep sleep.

Late-night eating, especially foods and drinks high in tyramine (an amino acid that triggers brain alertness), can also be a contributing factor. This includes aged cheeses, Italian wines, several beers, and cured meats. Kenny notes that tyramine stimulates the production of noradrenaline, a neurotransmitter involved in the sympathetic nervous system’s fight-or-flight response, which can make us feel alert and awake, preventing us from going to bed early.

Strategies for Achieving Restorative Slumber

Night owls can gradually adjust their schedules by changing food and sleep intake by 15 minutes per day until the desired sleep times are achieved, says Professor Kenny. She further recommends sleep-promoting foods that enhance neuropeptides such as tryptophan and melatonin. These foods include turkey, almonds, chamomile tea, fatty fish, kiwi, 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, Kenny adds.

Giles Watkins, author of Positive Sleep, advocates for going to bed and waking up at more or less the same time every day, as a strategy to fall asleep earlier and maintaining the rhythm of sleep.

A version of this article has been published by The Epoch Times.