How Do Sleep Patterns and Gender Affect PTSD Risk After Earthquakes?

What you need to know

• People’s natural sleep-wake patterns (chronotypes) may influence their risk of developing post-traumatic stress disorder (PTSD) after experiencing a traumatic event like an earthquake.
• This study found that “night owl” types had higher rates of PTSD symptoms compared to “morning lark” types among medical students who experienced major earthquakes in Turkey.
• Women were more likely than men to report PTSD symptoms after the earthquakes.
• Other factors like witnessing injuries/deaths and having loved ones affected also increased PTSD risk.

Understanding chronotypes and PTSD

Chronotype refers to a person’s natural inclination towards being a “morning person” or “night person.” This affects when we feel most alert and prefer to sleep. There are three main chronotypes:

1. Morning types (“larks”): Naturally wake up and feel alert early, prefer going to bed early
2. Evening types (“owls”): Naturally wake up later, feel most alert in the evening, prefer going to bed late
3. Intermediate types: Fall somewhere in between morning and evening types

Post-traumatic stress disorder (PTSD) is a mental health condition that can develop after experiencing or witnessing a traumatic event. Symptoms include intrusive memories, avoidance of reminders, negative mood changes, and heightened reactivity.

This study explored how chronotype might relate to PTSD risk in medical students who lived through major earthquakes in Turkey. Understanding these connections could help identify who may be most vulnerable after disasters and inform prevention efforts.

Study details and key findings

The researchers surveyed 193 medical students about 6 months after devastating earthquakes struck Turkey in February 2023. They assessed:

• Chronotype using a questionnaire
• PTSD symptoms using a clinical checklist
• Exposure to earthquake-related trauma (injuries, deaths, property damage)
• Demographic factors

Key findings included:

• 43.5% of students scored above the threshold for probable PTSD
• Evening types (“night owls”) had significantly higher PTSD symptom scores than morning types
• Women had higher PTSD rates (53.2%) compared to men (31%)
• Witnessing injuries/deaths and having loved ones affected by the earthquakes also increased PTSD risk

The chronotype-PTSD connection

Why might “night owls” be more vulnerable to PTSD? The researchers suggest a few potential explanations:

1. Evening types tend to have more irregular sleep patterns, which can negatively impact mental health.
2. The mismatch between evening types’ natural rhythms and typical work/school schedules may create chronic stress.
3. Evening types are more prone to depression and anxiety, which increase PTSD risk.
4. Trauma exposure may further disrupt sleep, creating a vicious cycle for evening types.

However, it’s important to note this was an observational study, so we can’t conclude chronotype directly causes higher PTSD risk. Other factors could be involved.

Gender differences in PTSD risk

The finding that women had higher rates of PTSD symptoms aligns with previous research showing women are at greater risk for PTSD after various types of trauma. Possible reasons for this include:

1. Biological differences in stress responses
2. Higher rates of previous trauma exposure in women
3. Societal factors that may make women more vulnerable
4. Differences in cognitive and emotional processing of trauma

Again, the exact mechanisms aren’t fully understood. But this highlights the importance of considering gender in PTSD prevention and treatment efforts.

Other risk factors for PTSD

Besides chronotype and gender, the study identified other factors associated with higher PTSD risk after the earthquakes:

• Witnessing injuries or deaths
• Having relatives who were injured
• Losing loved ones

These align with known PTSD risk factors related to the severity of trauma exposure and personal impact. They underscore how individual experiences during a disaster can affect mental health outcomes.

Implications for PTSD prevention and treatment

While we can’t change someone’s innate chronotype, understanding these connections could help target PTSD prevention and treatment efforts. Some potential implications include:

1. Screening for chronotype after disasters to identify those potentially at higher risk
2. Tailoring sleep hygiene interventions for evening types to improve sleep quality
3. Providing extra support and resources to women and those with high trauma exposure
4. Educating people about how sleep patterns may affect mental health after trauma
5. Considering chronotype when scheduling therapy sessions or support groups

More research is needed to determine the most effective strategies. But this study highlights the importance of considering individual differences in sleep patterns when addressing trauma and PTSD.

Limitations and future directions

As with any study, there are some limitations to consider:

• The sample was limited to medical students, who may not be representative of the general population
• PTSD was assessed by self-report questionnaire rather than clinical diagnosis
• The study was cross-sectional, so we can’t determine causation or how relationships may change over time

Future research could address these limitations by:

• Studying more diverse populations
• Using clinical interviews to diagnose PTSD
• Following people over time to see how chronotype affects PTSD development and recovery
• Exploring biological mechanisms linking chronotype and PTSD risk
• Testing interventions tailored to different chronotypes

Conclusions

• A person’s natural sleep-wake pattern (chronotype) may influence their risk of developing PTSD after experiencing trauma like an earthquake.
• “Night owl” types and women appear to be at higher risk for PTSD symptoms in this population of medical students.
• Understanding these individual differences could help improve PTSD prevention and treatment efforts after disasters.
• More research is needed to fully understand the connections between sleep patterns, gender, and PTSD risk across different populations and types of trauma.