Does All Sleep Loss Make Anxiety Worse?

How Different Sleep Loss Types Affect Our Brain’s Fear Response

Does Less Sleep Always Make Anxiety Worse?

Most of us know intuitively that poor sleep can affect our emotional state. So if disrupted sleep affects us a bit, then wouldn’t no sleep at all make things even worse?

A study published in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging looked at this very question, specifically looking at how different kinds of sleep loss affect our brain’s fear and safety learning systems – key processes for fear and anxiety conditions (Seo et al., 2020).

The results? Not what you’d expect.

Understanding Fear Learning and Safety Signals

Before we get into the research, it's helpful to understand that our ability to regulate fear isn't just about being “brave”.

To regulate fear, our brains use two ancient learning processes, “fear conditioning” – the learning process that is key to helping us recognize threats, and “fear extinction” – the learning process key to helping us recognize when something that was once threatening is now safe (Quirk & Mueller, 2008).

Fear Conditioning

This is how we learn to associate neutral things with danger. For example, if you've ever had a car accident at a particular intersection, your brain might learn to associate that location with threat and fear, causing anticipatory anxiety when you approach it again.

Fear Extinction

This is the process of learning that something previously threatening is now safe. Using the same example, as you successfully navigate that intersection multiple times without incident your brain gradually learns that it's no longer dangerous. In effect, your brain learns a new “safety” association that inhibits the old fear association.

So these two learning and memory processes are fundamental to our emotional wellbeing and actually form the basis of exposure therapy – the process behind our most effective treatments for anxiety disorders and PTSD (McNally, 2007).

The Brain-Sleep-Fear Connection

So what’s sleep got to do with this?

Well, scientists have known for some time that sleep aids memory consolidation across various systems in the brain (Walker & Stickgold, 2006). Sleep also plays a vital role in maintaining mental health and regulating emotions (Goldstein & Walker, 2014).

So what happens to fear and extinction learning if sleep is disrupted? Could this have implications for mental health?

That’s where the research from Seo et al., 2020 comes in.

The Research Setup: A Closer Look

The research team recruited 154 healthy young adults (56.3% female, average age 24.8 years) and randomly assigned them to three groups:

• Normal Sleep (NS): 48 participants who got their usual full night's sleep

• Sleep Restriction (SR): 53 participants who got only half their usual sleep

• Sleep Deprivation (SD): 53 participants who stayed awake all night

The sleep measurements indicated:

• Normal sleepers got about 449.4 minutes (≈7.5 hours) of sleep

• Sleep-restricted participants got 221.7 minutes (≈3.7 hours)

• Sleep-deprived participants stayed awake (though some dozed off for an average of 6.4 minutes)

The Fear Learning Process

The morning after their assigned sleep condition, participants went through three phases of fear learning and extinction learning involving images of furniture (desks and bookshelves) paired with mild electric shocks:

• Fear Conditioning: Learning to associate certain images with a mild shock

• Extinction Learning: Learning that these images were no longer paired with shocks and “safe”

• Extinction Recall: Testing their memory of the safety learning later that same day

But here's what made this study special - they used fMRI scanning, a type of brain scan, to watch participants' brains in action during these processes. This allowed them to see exactly which brain regions were activating or staying quiet under different sleep conditions.

Surprising Findings: Why Not All Sleep Loss Is Equal

The results painted an unexpected picture. Rather than showing a simple "worse with less sleep" pattern, different types of sleep loss affected fear processing in distinct ways:

Normal Sleep Group:

Participants who got regular sleep showed what researchers consider healthy brain responses:

• Showed strong activation in emotion regulation areas (rostral anterior cingulate cortex and ventromedial prefrontal cortex) during fear learning

• Engaged both fear (insula) and safety (orbital frontal cortex) networks during extinction learning

• Demonstrated balanced processing during recall

Sleep Restriction Group:

Getting half a night's sleep disrupted typical healthy fear regulation responses:

• More activated motor areas during fear learning, suggesting heightened physical threat response

• Showed limited engagement of extinction learning circuits

• Maintained stronger fear responses during recall, particularly in movement preparation areas

This pattern suggests the this group’s brains remained in a threat-responsive state even after safety learning.

Sleep Deprivation Group:

The totally sleep-deprived group showed a surprising pattern:

• Initially showed minimal brain activation during fear learning

• Like sleep restriction, didn't engage extinction circuits during learning

• Surprisingly, showed proper activation of both fear and safety circuits during recall, just delayed.

This suggests that total sleep deprivation may delay rather than prevent proper fear learning and regulation.

Is Disrupted Sleep Worse Than No Sleep?

Perhaps the most surprising finding was that partial sleep loss actually appeared more problematic than total sleep deprivation for fear processing.

The sleep-restricted group showed enhanced activity in fear-related brain regions and reduced activity in regulatory regions throughout the experiment.

As the researchers noted, this suggests that getting some poor quality sleep might be worse than no sleep at all when it comes to processing fearful and anxiety provoking experiences.

Why This Matters

Understanding how sleep affects fear processing isn't just academic curiosity. Consider these facts:

• People with pre-existing sleep problems are about 3 times more likely to develop anxiety disorders (Hertenstein et al., 2018)

• Sleep disturbance before trauma exposure increases PTSD risk (Wang et al., 2019)

• Sleep plays a crucial role in the success of exposure-based therapies (Pace-Schott et al., 2015)

This study provides valuable insights into the potential brain processes underlying why the above studies have made their findings.

Clinical Implications And Comment

These findings have significant implications for several groups:

• Individuals undergoing exposure therapy for anxiety or PTSD

• Shift workers with irregular sleep patterns

• First responders and military personnel who often operate under sleep restriction

• People with chronic sleep problems such as chronic insomnia, circadian rhythm disorders, nightmare disorder and restless legs syndrome

First, the research suggests that scheduling exposure therapy sessions when patients are well-rested might improve outcomes.

Second, it also raises concerns about the impact of chronic sleep restriction on emotional resilience in otherwise normal sleepers that have sleep disrupted by shift work or operational requirements that also involve exposure to threat and trauma (Germain et al., 2008). Organisations in these fields should be considering sleep questionnaires as part of mental health and wellbeing screening at a minimum.

Third, those with chronic sleep problems should consider how they are approaching their sleep.

When working with individuals with sleep problems it is common for them to adopt a “sleep at all costs” mentality and to see wakefulness as “undesirable” and a “threat”.

That may not be the case.

This research suggests that acute sleeplessness after a trauma, or particularly emotionally/physically activating event, may be a beneficial survival response of the body and brain. The body may be promoting wakefulness as a protective mechanism from the potential strengthening of the trauma or anxiety memory that would ensue if the person went to sleep and had a disrupted night’s sleep.

While a night without sleep would be uncomfortable in the short term, the longer term benefit would be improved fear extinction processing and reduced fear and anxiety.

So the common belief of people with sleep problems that they should force themselves to sleep or back to sleep because “some is better than none” may be perpetuating or even worsening their sleep problem by increasing anxiety levels the next day (this is occasionally noticed by some perceptive clients that comment they often feel worse returning to sleep after a night time wake up as opposed to “riding out” the rest of the night awake).

Fourth, this research supports recommended treatments for insomnia such as CBTi and Acceptance and Commitment Therapy for insomnia (ACTi). These therapy approaches, when done correctly, encourage patients not to try to sleep at all costs, but instead listen to what their body is telling them. These approaches also work to consolidate and enhance sleep quality, depth and continuity, which minimises sleep disruption.

Practical Takeaways For Sleep Health

While more research is always needed, this study suggests several practical considerations:

• If you’re a normal sleeper, prioritize getting good sleep quality (if you can) before potentially stressful situations.

• If you are struggling with sleep, be aware that chronic partial sleep loss might be more problematic than occasional all-nighters (some sleep is “bad”, no sleep may be “better”) especially after particularly traumatic or stressful situations;

• If you’re a therapist, consider sleep patterns when scheduling therapeutic interventions;

• If you have a chronic problem with sleep, seek a science-backed sleep therapy. And when you do, pay special attention to sleep quality, not just quantity

This study was published in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, (Seo et al., 2020)

References

Germain, A., Buysse, D. J., & Nofzinger, E. (2008). Sleep-specific mechanisms underlying posttraumatic stress disorder: Integrative review and neurobiological hypotheses. Sleep Medicine Reviews, 12(3), 185–195.  

Goldstein, A. N., & Walker, M. P. (2014). The role of sleep in emotional brain function. Annual Review of Clinical Psychology, 10, 679–708. https://doi.org/10.1146/annurev-clinpsy-032813-153716

Hertenstein, E., Feige, B., Gmeiner, T., Kienzler, C., Spiegelhalder, K., Johann, A., ... & Baglioni, C. (2018). Insomnia as a predictor of mental disorders: A systematic review and meta-analysis. Sleep Medicine Reviews, 43, 96-105.

McNally, R. J. (2007). Mechanisms of exposure therapy: how neuroscience can improve psychological treatments for anxiety disorders. Clinical Psychology Review, 27(6), 750-759.

Pace-Schott, E. F., Germain, A., & Milad, M. R. (2015). Sleep and REM sleep disturbance in the pathophysiology of PTSD: the role of extinction memory. Biology of Mood & Anxiety Disorders, 5(1), 3.

Quirk, G. J., & Mueller, D. (2008). Neural mechanisms of extinction learning and retrieval. Neuropsychopharmacology, 33(1), 56-72.

Seo, J., Pace-Schott, E. F., Milad, M. R., Song, H., & Germain, A. (2020). Partial and Total Sleep Deprivation Interferes with Neural Correlates of Consolidation of Fear Extinction Memory. Biological Psychiatry: Cognitive Neuroscience and Neuroimaging.

Walker, M. P., & Stickgold, R. (2006). Sleep, memory, and plasticity. Annual Review of Psychology, 57, 139-166.

Wang, H. E., Campbell-Sills, L., Kessler, R. C., Sun, X., Heeringa, S. G., Nock, M. K., ... & Stein, M. B. (2019). Pre-deployment insomnia is associated with post-deployment post-traumatic stress disorder and suicidal ideation in US Army soldiers. Sleep, 42(2), 1-9.

FAQ: Does All Sleep Loss Make Anxiety Worse?

1. Does less sleep always make anxiety worse?

While it's commonly believed that less sleep increases anxiety, research shows that different types of sleep loss have varying effects. A study by Seo et al. (2020) found that partial sleep loss can be more detrimental than total sleep deprivation in terms of fear processing.

2. What are fear conditioning and fear extinction?

Fear conditioning is the process where we learn to associate certain stimuli with danger, leading to anticipatory anxiety. Conversely, fear extinction is learning that a previously threatening stimulus is now safe. These processes are crucial for emotional well-being and play a significant role in exposure therapy for anxiety disorders (Quirk & Mueller, 2008).

3. How does sleep affect memory and emotional regulation?

Sleep is vital for memory consolidation and emotional regulation (Walker & Stickgold, 2006; Goldstein & Walker, 2014). Disrupted sleep may impair these functions, affecting how we process fear and safety signals.

4. What did the study by Seo et al. (2020) reveal about sleep loss and fear processing?

The study involved 154 young adults and compared their responses under three conditions: normal sleep, sleep restriction, and sleep deprivation. It found that those with sleep restriction exhibited heightened fear responses and limited engagement of extinction circuits, suggesting that partial sleep loss could hinder emotional regulation more than total sleep deprivation.

5. Are there implications for treatment regarding sleep and anxiety?

Yes, individuals undergoing exposure therapy for anxiety or PTSD may benefit from being well-rested prior to sessions. Additionally, chronic sleep issues can increase the risk of developing anxiety disorders (Hertenstein et al., 2018). Therefore, addressing sleep quality is crucial for mental health interventions.

6. What practical steps can individuals take to improve sleep health?

• Prioritize Quality Sleep: Aim for good sleep quality before stressful situations.

• Understand Sleep Patterns: Recognize that chronic partial sleep loss may be more harmful than occasional all-nighters.

• Seek Treatment: If you struggle with chronic sleep problems, consider therapies like Cognitive Behavioral Therapy for Insomnia (CBTi) which focus on improving sleep quality rather than just quantity