Course:EOSC311/2023/Shaken: Posttraumatic Stress Disorder in Earthquake Survivors
Introduction
When thinking about natural disasters, one will often imagine an earthquake at the forefront of their mind. To not be able to even depend on the very ground you stand on is a terrifying thought, yet for many, it is a reality. Earthquakes are so disastrous and mysterious that many myths have been created to account for their destruction.[1] However, often associated with many traumatic encounters, post-traumatic stress disorder is a very real implication and result of surviving an earthquake. It is said that 1 in 4 earthquake survivors experience post-traumatic stress disorder to some extent. [2]
Relationship to the Course and Major
Throughout Module 2 of EOSC 311, students discussed the phenomenon of plate tectonics and their movement.[3] This module expanded on plate interactions and boundaries (e.g., oceanic-continental, continental-continental, transform boundary etc) and what occurs at each type of boundary. Earthquakes are one of the events that occur at plate boundaries
Earthquakes
Earthquakes are easily one of the most common and destructive disasters to befall the earth. As mentioned in the introduction, earthquakes are also very mysterious, often explained through the use of myths and folklore. However, scientific hypotheses and theories were eventually developed to account for the terrible disasters. The cause of earthquakes was found to be due to plate movement.
Tectonic Plate Theory
Alfred Wegener and his theory of continental drift set the stage for the now well-known concept of plate tectonics.[4] Known as the "father of plate motion", he studied the continents very carefully, from their shape to the fossils that existed in each location, and hypothesized that they were all once connected as a supercontinent he coined, Pangea. At the time of his hypothesis, he was largely ridiculed as his theory did not suffice a medium for movement. It was not until 1965, well after his death, that there continental drift theory was widely accepted. While his theory of continental drift lacked the method of motion of such enormous plates i.e., continents, it was eventually discovered that there are several processes that allow for the plates to drift.
It was discovered that due to the nature of the extremely hot magma, it was constantly circulating in the mantle region, between the asthenosphere (lower part of the mantle) and the lithosphere (upper part of the mantle). The cool-heavy and hot-light dichotomy between magma material is what causes the constant convection that drives the motion of the plates. The circulation of the magma creates several phenomenon throughout the earth's crust. It pulls apart oceanic plates, which allows mantle material to rise and be pushed up into the earth's crust. This creates new sea-floor that pushes apart oceanic plates (the primary force behind continental drift). This phenomenon is called sea-floor spreading and is a type of plate boundary called divergent boundary.
Types of Boundaries[4]
By virtue of sea-floor spreading, the plates that are pushed will interact with other tectonic plates. In the case of an oceanic-continental plate collision, due to its dense nature and gravity, the oceanic plate will subduct under the continental plate. This type of plate boundary is called a convergent boundary. Due to the rise of magma as a result of subducting plates, volcanic arcs are often formed along convergent boundaries that can create volcanoes and mountains.
Another type of plate boundary is transform boundary in which plates slide past each other without damaging or altering the geological landscape. Earthquakes are prone to occur at any and all of these boundaries, but tend to occur most often at convergent boundaries.
Geological Process of Earthquakes
Earthquakes can occur anywhere in the world, but approximately 80% occur along the rim of the Pacific Ocean called the Pacific-seismic belt.[5] These earthquakes are primarily caused by tectonic plate motion, sometimes called tectonic earthquakes to differentiate between other types of earthquakes. Fault lines are typically where earthquakes will occur, due to the movement of tectonic plates. In the left figure, fault A refers to a transform boundary where plates slip past each other, while faults B & C refer to different results of convergent boundaries in which one or the other plate will subduct beneath the other.
When earthquakes occur, they generate three types of seismic waves:[5]
P Waves: (Primary waves) are the first waves to be detected by seismometers. These waves behave in a push-pull motion through rock and water.
S Waves: (Secondary waves) are the second waves to be detected. These waves move perpendicular to the direction the wave is going, and only through rock.
Surface Waves: are the ones felt along the surface of the earth. They move like ocean waves and cause the most damage
Post-Traumatic Stress Disorder
Introduction to Post-Traumatic Stress Disorder
Commonly known as "shell shock" or "battle fatigue", post-traumatic stress disorder (PTSD) has been highly prevalent throughout many instances of trauma. While there has been a controversy between the DSM-V (Diagnostic and Statistical Manual of Mental Disorders, Fifth edition) and ICD-11 (International Classification of Diseases), both reputable and standard guidelines for diagnosing psychological disorders. To be diagnosed with PTSD, the DSM-V requires that a person undergo or witness a traumatic event (e.g., death, violence, sexual abuse) exhibit a cluster range of symptoms such as intrusive distressing memories, avoidance of reminders of said trauma, and changes in cognition and/or mood. [6] The DSM-V's criteria for PTSD has a broadened scope compared to its ICD-11 counterpart, so for these purposes, we will use the DSM-V's definition.
From a neurological standpoint, PTSD is the process in which stress hormones experience a surge in conjunction with fear, creating strong association between the two.[6] These cues experienced by PTSD-patients are linked to predicting future threats, thereby causing immense fear and stress when the patient experiences internal or external reminders of the trauma.
Post-Traumatic Stress Disorder in Earthquake Survivors
I. In children and adolescents
Chungliao, Taiwan 1999
A study was performed to analyze the prevalence of PTSD in adolescent victims of the September 21, 1999 earthquake in Taiwan (7.3 on Richter scale)[7]. The subjects were extruded from a sample of survivors near the epicenter of the earthquake in Chungliao. Utilizing self-report questionnaires, 323 students aged 12-14 were interviewed and measured for PTSD in terms of psychiatric symptoms based on the Children's Interview for Psychiatric Syndromes. Among 323 students, only 21.7% were reported to have demonstrated symptoms of PTSD six weeks after the earthquake. The 2 major risk factors that heavily influenced the cases of PTSD were physical injury and the death of a household family member. While these prevalence results were not as high as other studies, it was suggested that impacted by the earthquake receive long-term followup treatment to ensure psychological wellbeing.
II. In adults
Chungliao, Taiwan 1999
A different study was performed on adult survivors in the same earthquake mentioned above.[8] Of the villages interviewed based on severity of destruction, PTSD was observed in 10.3% of the population and partial PTSD (not fulfilling all criteria of PTSD) in 19.0% of the population. While these results seem relatively low in comparison with other earthquakes, these results were recorded 2 weeks after the earthquake which might indicate that time-elapsed between disaster and recovery may be a variable in PTSD exhibition. Other variables that make it difficult to derive a definitive frequency of mental health consequences following earthquake disasters are variability in earthquake intensity, food and water resource availability, and sample selection.
Pisco, Peru 2007
5 months after an 8.0 magnitude earthquake struck Pisco, Peru, researchers performed a study to analyze the prevalence and risk factors of PTSD. [9] Through a cross-sectional study using questionnaires, the PTSD checklist, and the Harvard Trauma Questionnaire, researchers discovered that among 298 adult survivors, 75 reported symptoms of PTSD (prevalence rate of 25.2%). Through an additional bivariate analysis, it was found that women were more likely to experience PTSD than men, as well as other risk factors such as losing a church, basic needs, jobs, and friends. In a deeper multivariate analysis based on the results of the bivariate analysis, it was found that women lacking food and water after the earthquake were at most risk of experiencing symptoms of PTSD. An interesting thing to note is that religion and destruction of churches in earthquakes remained significant throughout the bi-multivariate analyses, indicating that faith-based communities act as a safe haven for many, particularly in developing nations as these results are not exclusive to Peru.
Systemic Review and Meta-analysis
Out of 46 articles that fulfill the quantitative and qualitative search requirements of earthquake-induced PTSD, a meta-analysis was performed to analyze the prevalence rate of PTSD in earthquakes ranging from magnitude 4.3 to 9.0.[10] It was found that the combined incidence rate of PTSD among earthquake survivors was 23.66% Going further in a subgroup analysis, it was discovered that there was a 28.76% prevalence rate for survivors assessed within 9 months of the disaster, while a there was a 19.48% prevalence rate in survivors assessed over 9 months after their disaster. Risk factors that might aggravate PTSD symptoms include loss of home, bereavement, injury and death. Similar to the study done in Peru 2007, women were more likely to experience PTSD symptoms, as well as the lesser-educated.
Treatment of PTSD
In the treatment of post-traumatic stress disorder, there are many treatment plans and approaches clinicians can make. Some treatment programs can also be adapted for specific causes such as earthquakes.
Cognitive Behavioural Therapy
Modified Behavioural Treatment - Marmara, Turkey 1999
In a clinical trial, researchers used modified behavioural treatment (BT) on adult victims of the 1999 Marmara earthquake in Turkey 13 months after the disaster.[11] The treatment involved focusing on increasing one's sense of control over distressing trauma. It required the patient to first identify the problems they encounter, and then exhibit either dominance over it or subjection to it. After patients had mastered their psychological wellbeing, they were assigned to exposure to one of four functionally disabling problems that were reported (e.g., sights of devastation, building safety). The exposure component of the treatment was largely unsupervised as it was up to the patient to overcome their fear.[11] While there was no control group to measure baseline results, the large, positive effect sizes as a result of the modified BT trials were enough to demonstrate improvement of PTSD and depressive symptoms. It was also surprising to discover that the immensely positive results were attainable after only a few sessions (mean of 3-4 sessions). Significant results were observed 76% of the time after one session, and 88% after two sessions.[11]
Psychoeducation
Psychoeducation with Medication - Marmara, Turkey 1999
In a clinical trial using 51 participants of the same Marmara 1999 disaster, a psychoeducation intervention was used to assess efficacy.[12] The intervention included 6 weekly sessions of problem solving and progress reporting through interviews based on Peplau's interpersonal relationship model. Assessments were made using the Clinician Administered PTSD Scale (CAPS), Hamilton Depression Scale (HDS), and Coping Strategies Scale (CSS). Throughout this study, there were three groups: psychoeducation only, medication only, and psychoeducation with medication. The results yielded positive outcomes from the psychoeducation with medication group, but were faced with symptoms of anxiety and hyperarousal that can affect treatment. Despite the decrease observed throughout the psychoeducation sessions, coping strategies such as avoidance, remained.
Coping Strategies
Coping strategies are mechanisms that everyone uses to cope with trauma and disaster. While some may be beneficial longterm, many can be maladaptive. In a study of survivors 10 months after the 2015 Nepal earthquake, it was found that with a PTSD prevalence rate of 24.10%, many adult survivors turn to coping strategies as treatment programs were unavailable.[13] The highest used strategy was active coping (controlling a stressor through moderately engaging the targeted behaviour), social coping (seeking emotional and gregarious support from a community), and religious practice, all of which are very effective and beneficial coping strategies. However, when it came to adults with PTSD, maladaptive coping strategies such as passive coping (e.g., avoidance, denial, withdrawing) and substance abuse, were used.
Conclusion
Earthquakes are a terrible, sudden, and destructive disaster that can cause severe misfortune for many people. While the prevalence of earthquakes are not specifically rising,[14] the risk of disaster remains the same. With greater populations and slowly decaying buildings, injury and death are a large possibility for many in high-risk areas. Despite bodily injuries and death, psychological disorders can also occur as a result of the earthquakes. The link between earthquakes and psychology is blatant as many, up to 28% of earthquake survivors, experience symptoms of post-traumatic stress disorder. Treatment and coping strategies are available to help heal, but it remains a fact that PTSD is a very real consequence of earthquakes.
References
- ↑ Milford Public Library (2009). "Fantastic Folklore: Earthquake Myths". Milford Public Library. Retrieved June 20, 2023.
- ↑ Dai, W., Chen, L., Lai, Z., Li, Y., Wang, J., & Liu, A. (2016). The incidence of post-traumatic stress disorder among survivors after earthquakes: a systematic review and meta-analysis. BMC Psychiatry 16, 188. https://doi.org/10.1186/s12888-016-0891-9
- ↑ Porritt, Li. (n.d.) Plate tectonics [Module 2]. Canvas. https://canvas.ubc.ca/courses/116917/pages/module-2-plate-tectonics?module_item_id=5380073
- ↑ 4.0 4.1 Earle, S. (2019). Physical Geology, First University of Saskatchewan Edition. (K. Panchuk Ed.). Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. https://openpress.usask.ca/physicalgeology/
- ↑ 5.0 5.1 Caltech. (n.d.) What Happens During an Earthquake? https://scienceexchange.caltech.edu/topics/earthquakes/what-causes-earthquakes
- ↑ 6.0 6.1 Bryant, R.A. (2019). Post-traumatic stress disorder: a state-of-the-art review of evidence and challenges. World Psychiatry, 18: 259-269. https://doi.org/10.1002/wps.20656
- ↑ Hsu, C., Chong, M., Yang, P., & Yen, C. (2002). Posttraumatic stress disorder among adolescent earthquake victims in Taiwan. Journal of the American Academy of Child & Adolescent Psychiatry, 41(7). 875-881. https://doi.org/10.1097/00004583-200207000-00022
- ↑ Lai, T. J., Chang, C. M., Connor, K. M., Lee, L. C., & Davidson, J. R. (2004). Full and partial PTSD among earthquake survivors in rural Taiwan. Journal of psychiatric research, 38(3), 313–322. https://doi.org/10.1016/j.jpsychires.2003.08.005
- ↑ Cairo, J., Dutta, S., Nawaz, H., Hashmi, S., Kasl, S., & Bellido, E. (2010). The Prevalence of Posttraumatic Stress Disorder Among Adult Earthquake Survivors in Peru. Disaster Medicine and Public Health Preparedness, 4(1), 39-46. doi:10.1017/S1935789300002408
- ↑ Dai, W., Chen, L., Lai, Z., Li, Y., Wang, J., & Liu, A. (2016). The incidence of post-traumatic stress disorder among survivors after earthquakes: A systematic review and meta-analysis. BMC Psychiatry, 16(1). https://doi.org/10.1186/s12888-016-0891-9
- ↑ 11.0 11.1 11.2 Başoğlu, M., Livanou, M., Salcioğlu, E., & Kalender, D. (2003). A brief behavioural treatment of chronic post-traumatic stress disorder in earthquake survivors: results from an open clinical trial. Psychological medicine, 33(4), 647–654. https://doi.org/10.1017/s0033291703007360
- ↑ Oflaz, F., Hatipoğlu, S., & Aydin, H. (2008). Effectiveness of psychoeducation intervention on post-traumatic stress disorder and coping styles of earthquake survivors. Journal of Clinical Nursing, 17. 677-687. https://doi.org/10.1111/j.1365-2702.2007.02047.x
- ↑ Adhikari Baral, I., & K.C, B. (2019). Post traumatic stress disorder and coping strategies among adult survivors of earthquake, Nepal. BMC Psychiatry, 19(1). https://doi.org/10.1186/s12888-019-2090-y
- ↑ Chandler, Jenny (January 24, 2023). "Are we having more earthquakes than usual?". AF8: Alpine Fault Magnitude 8. Retrieved June 21, 2023.
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