Past
stressful experiences do not create resilience to future trauma, new study
finds
By Kerry Benson, Brown
University
 |
| In the rubble of Chile's 2010 major earthquake and tsunami |
The findings suggest that the Chilean disaster survivors who had experienced multiple stressors and traumas were at a greater risk of developing a post-disaster mental health disorder compared to those who had experienced few or no prior stressors.
What doesn’t kill you makes you
stronger — that claim is so universally accepted that it’s a common truism in
contexts from everyday conversations to Top 40 pop charts.
In fact, the research suggests the
opposite is true: Past stressors sensitize people to future traumas, thereby
increasing their chances of developing a mental health disorder.
“We hope that this research will
spur interest in the face of the increasing number of natural disasters per
year — a major consequence of climate change — such as the devastating
earthquake that affected Chile and neighboring countries,” said Cristina
Fernandez, a psychiatric epidemiologist and the study’s lead author.
“The immediate global impacts of these catastrophic events on disease, death and the economy are largely well-recognized. Unfortunately, despite a high disease burden, mental illness has thus far not achieved commensurate visibility, policy attention or funding.”
“The immediate global impacts of these catastrophic events on disease, death and the economy are largely well-recognized. Unfortunately, despite a high disease burden, mental illness has thus far not achieved commensurate visibility, policy attention or funding.”
The study, published in the British Journal of Psychiatry on Thursday, June 11, was a collaborative effort led by scientists at Brown and the University of Concepción in central Chile.
The team examined 1,160 Chileans in
2003 and 2011 — both before and after the sixth-most-powerful earthquake on
record and subsequent tsunami struck their country in 2010.
When the study began in 2003, none of the participants had a history of post-traumatic stress disorder (PTSD) or major depressive disorder (MDD). After the 2010 earthquake, 9.1% of the survivors were diagnosed with PTSD and 14.4% with MDD.
When the study began in 2003, none of the participants had a history of post-traumatic stress disorder (PTSD) or major depressive disorder (MDD). After the 2010 earthquake, 9.1% of the survivors were diagnosed with PTSD and 14.4% with MDD.
The risk of developing these
disorders was particularly high among individuals who experienced multiple
pre-disaster stressors, such as serious illness or injury, death of a loved
one, divorce, unemployment or financial struggles, legal troubles or loss of a
valuable possession.
To be at increased risk for post-disaster PTSD (relative to those with zero stressors), individuals had to have crossed a “severity threshold” of four or more pre-disaster stressors.
To be at increased risk for post-disaster PTSD (relative to those with zero stressors), individuals had to have crossed a “severity threshold” of four or more pre-disaster stressors.
MDD displayed a slightly different
pattern: Every pre-disaster stressor — even a single stressor — increased a
person’s risk of developing post-disaster MDD, and each additional stressor
further increased the risk.
The researchers say that overall,
both findings suggest that the Chilean disaster survivors who had experienced
multiple stressors and traumas were at a greater risk of developing a
post-disaster mental health disorder compared to those who had experienced few
or no prior stressors.
“Unfortunately, the same may well
hold true with COVID-19,” said Stephen Buka, a professor of epidemiology at
Brown’s School of Public Health and senior author of the paper.
“We’re already witnessing how black and Latino Americans are experiencing higher rates of [COVID-19] infections and fatalities. All evidence suggests that disadvantaged groups, who frequently have higher levels of prior life stresses — such as limited finances and job instability — will be most likely to suffer the most from serious mental health conditions following the pandemic.”
“We’re already witnessing how black and Latino Americans are experiencing higher rates of [COVID-19] infections and fatalities. All evidence suggests that disadvantaged groups, who frequently have higher levels of prior life stresses — such as limited finances and job instability — will be most likely to suffer the most from serious mental health conditions following the pandemic.”
The team hopes its research will
help other countries understand the importance of accessible mental health
care.
“Personal and national mental health
preparedness kits, such as the ones utilized in Chile, help mitigate the
negative effects of disasters and can serve as a model for other countries,”
said Benjamin Vicente, a principal investigator of the study from the
University of Concepción.
“Along with strict building codes, [Chile] has a national health care service, which includes integrated primary and mental health care centers, most of which have trained personnel to provide disaster coping strategies when needed.”
“Along with strict building codes, [Chile] has a national health care service, which includes integrated primary and mental health care centers, most of which have trained personnel to provide disaster coping strategies when needed.”
In addition to Fernandez and Buka,
other Brown University authors on the study were Robert Kohn and Brandon
Marshall. Additional contributors were Vicente and Sandra Saldivia from the
University of Concepción, Karestan Koenen and Karmel Choi from Harvard
University, and Kristopher Arheart from the University of Miami.
The study was supported by the
National Institute of Mental Health (F31MH104000 and 5T32MH017119-30) and
FONDEF Chile (D021-1140 and 1110687).