Health · Medical Research · 6 hrs ago
Study links insomnia with difficulty learning that a threat has passed
Researchers found a link between insomnia and difficulty regulating fear in a study using skin conductance, a measure of stress-related arousal.
The study compared 24 adults with insomnia and 24 good sleepers who completed a task involving a visual stimulus paired with a mild shock.
Participants then learned that the stimulus no longer signalled danger, a process called fear extinction.
Only a model that included continuous background skin signals found a significant group difference; a model measuring only sharp stress spikes did not.
As the threat was removed, arousal rose in the insomnia group but fell slightly among good sleepers.
The researchers suggest that people with insomnia may form or retain a weaker memory that the stimulus is safe, leaving the original fear response harder to override.
The findings may help explain why exposure therapy works better in people who sleep well, but the study does not establish that insomnia causes problems with fear regulation.
A study found that adults with insomnia showed a different pattern of physiological responses while learning that a threat was no longer dangerous.
Researchers analyzed skin conductance from 24 adults with insomnia and 24 good sleepers during a fear-learning task.
Only a model that included continuous background skin conductance detected a significant difference between the groups.
The average high-arousal index rose from fear conditioning to extinction in participants with insomnia, but fell slightly in good sleepers.
The researchers said the findings suggest insomnia may be linked to difficulty acquiring or retaining a safety memory.
- Who
- Researchers led by Dr. Rose T. Faghih of New York University Tandon School of Engineering, with collaborators at Harvard Medical School, studied adults with insomnia and good sleepers.
- What
- The study found a significant difference in fear and safety responses over time between the groups, detected by a model incorporating background skin conductance.
- When
- The study was published the week of October 14, 2026.
- Where
- The study was published in PLOS Mental Health. The researchers were based at New York University Tandon School of Engineering and Harvard Medical School in the US.
- Why
- The researchers investigated whether insomnia is associated with differences in learning and remembering that a threat has passed.
This story does not have two clearly opposing sides.
Participants were temporarily conditioned to fear a visual stimulus by pairing it with a mild shock.
Participants learned that the visual stimulus was no longer dangerous.
Researchers assessed recall of the fear and safety memories.
The study was published in PLOS Mental Health.
- Study sample
- 24 adults with insomnia and 24 good sleepers
- Study journal
- PLOS Mental Health
- Insomnia prevalence estimate
- 10% of the population
- Significant model
- The model incorporating continuous background skin conductance detected a difference between groups
- Arousal pattern
- High-arousal index increased in participants with insomnia and decreased slightly in good sleepers from conditioning to extinction
What people are saying
Our study shows that insomnia isn't just about poor sleep-it directly relates to the body's ability to learn and remember that a threat is gone.
This hyperarousal could oppose subsequent learning that a stimulus has become safe, which may explain why anxiety treatments like exposure therapy are more successful in people with good sleep.
Using our previously developed sympathetic arousal virtual sensors based on microfluctuations in sweat activity, we compared insomnia patients and healthy controls during fear extinction and observed that insomnia is associated with a reduced capacity to extinguish physiological threat responses.