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In a nutshell
- Poor sleep quality significantly increases your susceptibility to conspiracy theories, creating a feedback loop where sleep issues and conspiracy beliefs may reinforce each other.
- Depression serves as the strongest psychological link between sleep problems and conspiracy beliefs, with anger and paranoia playing smaller but notable roles.
- Improving sleep quality could be an unexpected but effective way to reduce vulnerability to conspiracy theories and misinformation, offering benefits for both mental health and critical thinking.
NOTTINGHAM, England — Why do some people fall for conspiracy theories while others don’t? Research has typically focused on political beliefs and personality traits, but scientists have uncovered a surprising everyday factor that might be making us more susceptible to conspiracy thinking: not getting enough sleep.
New research from the University of Nottingham, published in the Journal of Health Psychology, reveals that people who sleep poorly are likelier to believe conspiracy theories, especially after seeing conspiracy content. This link exists both for people with ordinary sleep problems and those with clinical insomnia, suggesting our sleep habits might affect how we process information.
Conspiracy theories increasingly affect public health decisions like vaccine uptake and our response to climate change. Figuring out why people believe these theories has become critically important.
The Research: Poor Sleep and Conspiracy Beliefs
Dr. Daniel Jolley and his team ran two studies with over 1,100 participants to see how sleep affects our thinking and mental state.
“We know a lot about the cognitive biases, social influences, and personal traits that explain why people believe in conspiracy theories. However, previous research has typically overlooked how sleep, especially poor-quality sleep, may impact conspiracy beliefs,” Jolley tells StudyFinds. “We also wanted to explore the potential mechanisms behind this connection.”
The team found that when we don’t sleep well, we get irritable and our thinking becomes fuzzy. This mental fog seems to make conspiracy theories—stories about secret plots behind major events—more convincing than they otherwise would be.
In their first experiment with 540 people, the researchers measured sleep quality and then randomly showed participants either a conspiracy theory about the 2019 Notre Dame Cathedral fire or a non-conspiracy explanation. Those who reported poor sleep and read the conspiracy version were much more prone to believing conspiracy theories about the fire compared to well-rested people. This effect was strongest in participants with terrible sleep.
The second study with 575 participants dug into the psychological reasons for this connection. Researchers measured their levels of anxiety, anger, depression, and paranoia. They also assessed their conspiracy mentality (a general tendency toward conspiratorial thinking) and belief in specific conspiracy theories.
Depression consistently linked poor sleep to conspiracy beliefs, while anger and paranoia showed some connection but less consistently.
This creates what the researchers call a “sleep cycle of conspiracy beliefs”—a worrying feedback loop where bad sleep hurts your mental health, making you more vulnerable to conspiracy theories, which might then make your sleep and mental health even worse.
Around 74% of people reported worse sleep quality over a recent 12-month period, according to polling data mentioned in the study. Unlike clinical insomnia (affecting 10-20% of people), garden-variety poor sleep is extremely common yet often dismissed as normal in our busy culture. This widespread sleep deprivation could be quietly feeding the spread of conspiracy theories across society.
The Psychology Behind the Connection
The link between sleep and conspiracy thinking works mainly through depression. When sleep suffers, so does our emotional balance, potentially leading to depressive feelings. For someone feeling low, conspiracy theories can serve as a coping mechanism—projecting bad intentions onto others that match their negative emotional state.
The paper notes that for people experiencing depression, conspiracy theories might align better with their worldview, making a conspiracy-filled world feel more coherent than alternative explanations.
Curiously, anxiety—often linked to both sleep problems and conspiracy beliefs in previous studies—didn’t emerge as a significant factor in this research. This unexpected finding shows how complex the relationship between sleep, emotions, and conspiracy thinking really is.
“While our study links poor sleep to conspiracy beliefs, it doesn’t establish a cause-and-effect relationship. Nonetheless, we show that sleep and conspiracy beliefs are linked,” says Jolley, an assistant professor in social psychology at Nottingham. “We also know from previous research that sleep deprivation can directly increase anxiety, anger, and feelings of depression, which are predictors of conspiracy beliefs. We argue that by prioritizing good sleep, individuals can improve both their mental and physical health, which will likely strengthen their ability to think critically and resist misinformation in an increasingly complex world.”
The Power of a Good Night’s Rest
So does improving sleep quality make a person less susceptible to believing in conspiracy theories?
“We do not know yet,” says Jolley. “Our research measured sleep quality using a standard assessment tool. It would be fantastic for future research to conduct controlled experiments to examine how poor sleep might contribute to conspiracy beliefs. For example, studying whether participants in an acute sleep deprivation study show heightened conspiracy beliefs. From our work, we can only conclude that the two are interlinked.”
The good news is that sleep habits can be changed. Unlike deep-seated personality traits or political beliefs, sleep can be improved through various methods. This points to a novel approach to fighting the spread of conspiracy theories: promoting better sleep across the population.
Better sleep might deliver two benefits at once—improving overall mental health while reducing vulnerability to conspiracy theories.
For parents worried about teens encountering online misinformation, or health officials battling vaccine conspiracy theories, this research offers practical advice: addressing sleep problems might be an unexpected but useful part of the solution.
The study also challenges standard approaches to debunking conspiracy theories. Rather than only presenting facts—which often fail against entrenched conspiracy beliefs—addressing underlying psychological states that make conspiracy theories appealing might work better.
In today’s information environment, with its constant barrage of claims, maintaining critical thinking is vital. Perhaps one of our best defenses is something surprisingly simple: sleeping well.
Paper Summary
Methodology
The Nottingham team ran two different studies. For Study 1, they gathered 540 participants through Prolific, an online research platform. First, they had everyone complete the Sleep Quality Scale to check their sleep patterns over the previous month. Then they randomly assigned people to read either a conspiracy theory or a factual article about the 2019 Notre Dame Cathedral fire. After reading, participants rated how much they believed conspiracy theories about the fire.
For Study 2, they recruited 575 participants who completed both the Sleep Quality Scale and the Insomnia Severity Index. Participants also filled out questionnaires measuring anxiety, anger, depression, and paranoia, plus assessments of conspiracy mentality (general tendency toward conspiratorial thinking) and belief in specific conspiracy theories. The researchers used path analysis to identify which psychological factors might connect sleep quality to conspiracy beliefs.
Results
Study 1 showed that people exposed to conspiracy theories about the Notre Dame fire believed those theories significantly more than people who read factual information. More importantly, sleep quality affected this relationship – people who slept poorly showed a stronger increase in conspiracy beliefs after seeing conspiracy content compared to better sleepers.
In Study 2, both poor sleep quality and insomnia correlated positively with conspiracy mentality and specific conspiracy beliefs. When examining the mediating factors, depression consistently emerged as the significant link between sleep problems and both types of conspiracy beliefs. Paranoia connected sleep quality and insomnia to specific conspiracy beliefs, while anger connected insomnia to specific conspiracy beliefs. Surprisingly, anxiety didn’t connect sleep problems and conspiracy beliefs as expected.
Discussion and Takeaways
The research provides strong evidence that poor sleep quality increases vulnerability to conspiracy theories through its effects on psychological well-being, particularly depression. These findings suggest that improving sleep quality could protect against the spread of conspiracy theories and their negative consequences.
The researchers propose a “sleep cycle of conspiracy beliefs” – a feedback loop where poor sleep harms mental well-being, increasing conspiracy beliefs, which might further disrupt sleep. Breaking this cycle by addressing either sleep problems or conspiracy beliefs could potentially help with both issues.
The study highlights sleep as a modifiable risk factor for conspiracy beliefs, alongside other factors like ideology or personality traits. This offers a practical approach to reducing vulnerability to misinformation by focusing on sleep improvements.
Limitations
The researchers point out several limitations. First, they relied on participants reporting their own sleep quality and insomnia symptoms rather than using objective measurements like sleep monitors. While self-reporting is valid for sleep research, objective measurements might provide additional insights.
Second, Study 2’s correlational design limits conclusions about causation. Although Study 1 manipulated exposure to conspiracy theories, it didn’t manipulate sleep quality itself. Future studies could benefit from experimental designs that alter sleep quality or track changes over time.
Funding and Disclosures
The authors declared no conflicts of interest regarding their research, authorship, or publication. They received no financial support for conducting this research. The University of Nottingham’s School of Psychology Ethics Committee (#F1499) approved the study, and all participants provided informed consent.
Publication Information
“Investigating the link between sleep quality and belief in conspiracy theories” was written by Daniel Jolley, Iwan Dinnick, Lauren Burgin, Sophie Ryan, Olivia Morgan-Finn, and Samuel Muncer from the University of Nottingham. It appeared in the Journal of Health Psychology in 2025. The research data, pre-registration documents, and materials are available at https://osf.io/hzevx/.
