Lack of Sleep Spikes Anxiety by 30%, While Deep Sleep Resets the Brain’s Emotional Control, Per UC Berkeley Research

Key Takeaways

Sleep Deprivation Fuels Anxiety: A single sleepless night can spike anxiety by up to 30%, destabilizing the brain’s emotional regulation.
Deep Sleep Resets the Brain: Non-REM (deep sleep) restores the prefrontal cortex’s control over emotional centers, acting as a natural anxiety buffer.
Sleep Quality Over Quantity: Even small improvements in deep sleep reduce next-day anxiety, offering a drug-free strategy for mental health.

Research out of the University of California, Berkeley has again emphasized the importance of restful nightly sleep with regard to emotional health.

Poor Sleep Raises Anxiety By 30%
(Graphic courtesy of Eti Ben Simon)

When a person is unable to sleep well at night, their anxiety levels can surge by up to 30 percent, according to the study. A night full of sleep, on the other hand, soothes the anxious brain.

Findings from the study appeared in Nature Human Behavior. They provide very strong evidence of the neural links of sleep to anxiety.

The researchers reported that the particular type of sleep that produced the most restful effect was deep sleep. This sleep state, also referred to as non-rapid eye movement (NREM) sleep, is described as one of “behavioral and physiological quiescence.” While in it, neural oscillations become well synchronized, with both blood pressure and heart rates falling.

“Deep sleep seems to be a natural anxiolytic (anxiety inhibitor), so long as we get it each and every night,” said Matthew Walker, study senior author and a professor of neuroscience and psychology at UC Berkeley.

The study suggests sleep is a natural alternative to drugs for managing anxiety disorders, cases of which are rising in America.

Sleep and stress connection

The researchers made their findings in a series of experiments involving a full night of sleep and a night of no sleep. They first recruited 18 young adults for their study. These subjects were made to view video clips that were emotionally moving after a full night of sleep and also after a wakeful night.

While the subjects viewed the clips, researchers scanned their brains. They also used the state-trait anxiety inventory, a questionnaire, to assess the anxiety levels of the participants after each session.

The sleepless night resulted in the failure of the medial prefrontal cortex, an area of the brain helping with anxiety control. There was also over-activity in the deeper emotional centers of the brain.

Walker described the effect of a sleepless night as “almost as if the brain is too heavy on the emotional pedal, without enough brake.”

A night of no sleep caused anxiety levels to spike by up to 30 percent, the researchers found.

The results showed, on the other hand, that a full night of sleep led to a considerable drop in anxiety levels. This effect was particularly marked in subjects who had better NREM sleep. The brain waves of the participants were evaluated with the aid of electrodes placed on their heads.

“Deep sleep has restored the brain’s prefrontal mechanism that regulates our emotions, lowering emotional and physiological reactivity and preventing the escalation of anxiety,” said Eti Ben Simon, study lead author and a postdoctoral fellow at UC Berkeley’s Center for Human Sleep Science.

The scientists were also able to replicate their results in another study of 30 subjects. They observed that participants who had more deep sleep the previous night had the lowest anxiety levels during the day that followed.

Fighting anxiety issues

Anxiety disorders are a big problem in the industrialized world. Around 40 million adults in the United States alone suffer from an anxiety disorder. The incidence of the conditions is rising among children and teenagers as well.

The UC Berkeley researchers also carried out an online study, in addition to their lab experiments. They assessed variations in sleep and anxiety levels of 280 people over four days. Their findings showed that the amount of sleep participants got on any night determined their anxiety level the day after.

Slight changes in sleep still produced an effect on the anxiety levels of the subjects.

According to Walker, the findings imply that “the decimation of sleep throughout most industrialized nations” is possibly a major contributor to the increasing incidence of anxiety disorders in those countries.

Yet, sleep is hardly considered a standard recommendation for combating anxiety, the researchers noted.

Simon said the study confirms the causal relationship between sleep and anxiety. Also, deep sleep appeared to be particularly useful for dealing with anxiety disorders.

“Our study strongly suggests that insufficient sleep amplifies the levels of anxiety and, conversely, that deep sleep helps reduce such stress,” he said.

Sleep & Anxiety FAQs: How Deep Sleep Rewires the Anxious Brain

How does poor sleep increase anxiety?
Lack of sleep weakens the prefrontal cortex (the brain’s “brake” on emotions) and overactivates emotional centers, heightening stress responses.

What defines “deep sleep” (NREM)?
Deep sleep involves synchronized brain waves, lowered heart rate, and physiological calm. It’s critical for emotional reset and memory consolidation.

How much deep sleep is needed to reduce anxiety?
The study didn’t specify exact hours, but participants with more NREM sleep showed the lowest anxiety. Aim for 1.5–2 hours of deep sleep nightly (20–25% of total sleep).

Can improving sleep replace anxiety medication?
Not universally, but the study positions deep sleep as a complementary, natural therapy. Always consult a doctor before adjusting medication.

Did the study only focus on young adults?
Initial experiments involved 18 young adults, but findings were replicated in a 30-person study and an online survey of 280 diverse ages, strengthening reliability.

How was anxiety measured?
Researchers used brain scans (fMRI), the State-Trait Anxiety Inventory questionnaire, and tracked emotional reactions to stressful video clips.

Does this apply to chronic anxiety disorders?
Yes 40 million U.S. adults have anxiety disorders, and sleep disruption is a likely contributor. Deep sleep may help manage symptoms.

Can naps compensate for poor nighttime sleep?
Naps lack sufficient deep sleep cycles. Prioritize uninterrupted nighttime sleep for anxiety relief.

What practical steps boost deep sleep?

Keep a consistent sleep schedule.
Avoid screens before bed (blue light disrupts sleep cycles).
Cool, dark rooms and mindfulness practices (e.g., meditation) enhance sleep quality.

Are sleep aids (e.g., melatonin) recommended?
Short-term use may help, but focus on natural sleep hygiene first. Over-reliance on aids can disrupt deep sleep phases.

Does this research apply to children/teens?
Yes—anxiety is rising in youth. Prioritizing sleep could mitigate risk, though more studies are needed in younger populations.