Original studyFrontiers in Psychology, 2026Read the paper →
Istanbul lies close to the North Anatolian Fault, and scientists have warned for years of a substantial chance of a major earthquake in the Marmara region. Sleep problems are well documented after large disasters, but far less is known about life under the threat of one. A new Turkish study suggests that feeling constantly on edge about the expected quake goes hand in hand with more severe insomnia.
Researchers at Erzincan Binali Yildirim University and Ondokuz Mayis University in Turkey surveyed 416 adults living in Istanbul. The study appears in Frontiers in Psychology. Data were collected through an online survey shared on social media.
People who had lost a close family member or had their home destroyed in a previous earthquake were excluded, so the study focused on residents living with the threat rather than its aftermath. Just over two thirds of participants were women, and a similar share were aged 18 to 30. Most held a bachelor’s degree.
Participants were asked to think about recent scientific warnings and media reports about the expected Marmara earthquake. They then rated how much these had affected them on three trauma-related scales. Intrusion covers unwanted thoughts or images of a future quake, avoidance covers efforts to push such thoughts away, and hyperarousal covers feeling constantly alert and unable to relax.
Insomnia was measured with a standard seven-item questionnaire covering trouble falling and staying asleep, waking too early, and the toll on daytime life. Depression, anxiety, and stress were measured too. Insomnia was linked with all of these, and most strongly with hyperarousal.
When the three trauma-related scales were analysed together, hyperarousal was the only one still tied to insomnia, and together they accounted for just over half the variation in insomnia scores. Insomnia did not differ significantly between men and women or across age groups. Taking gender and age into account left the link with hyperarousal largely unchanged.
Hyperarousal was closely tied to stress, so the team ran exploratory tests of whether depression, anxiety, or stress might explain its connection with poor sleep. They did not. Once hyperarousal was taken into account, none of the three was linked to insomnia on its own.
The hyperarousal scale includes one question about trouble falling asleep, which overlaps with the insomnia questionnaire. When that question was removed, the link with hyperarousal weakened considerably but stayed statistically significant, and intrusive thoughts about a future quake became the strongest predictor of insomnia. The authors say this overlap may partly explain how strong the original link appeared.
The study has clear limits. It captured a single point in time, so it cannot show whether worry about an earthquake disrupts sleep, whether poor sleep heightens arousal, or whether both stem from something else such as existing anxiety. Media exposure was not measured directly, answers were self-reported, and the sample was largely young, female, and university educated, so the findings may not apply to all Istanbul residents or to earthquake survivors.
The authors suggest that asking about arousal-related symptoms may help when assessing sleep problems in people living under disaster threat. Cognitive behavioural approaches to insomnia and relaxation techniques may be worth considering, although whether they help in this setting has not been tested. Studies that follow people over time are needed to untangle cause and effect.
