Disasters and Trauma:
What We Have Learned from
9/11 and Hurricane Katrina
William E. Schlenger, Ph.D.
Abt Associates Inc.
Presentation Overview
• Brief Overview of Psychological Trauma Basics
• Brief Review of Traumatic Exposures and Outcomes of
9/11
• Brief Review of Traumatic Exposures and Outcomes of
Hurricane Katrina
• Priority issues in Service Delivery in the Aftermath of
Disaster
Psychological Trauma Basics
• Mental health practitioners use the word trauma to refer to
“a wide range of intensely stressful experiences that
involve exposure to levels of danger and fear that exceed
normal capacity to cope”
• The basic epidemiology of exposure to a wide variety of
potentially traumatic events (PTEs) has been well
documented in recent decades
Psychological Trauma Basics (cont.)
• Majority of U.S. population is exposed to at least one PTE
in their lifetime, and many exposed to more than one
• Across a broad range of large scale PTEs, most of those
exposed experience some distress (e.g., intense fear,
anger, sorrow, uncertainty) but do not have any clinically
significant mental health sequelae
• In the subset that does experience clinically significant
reactions, the reactions typically include PTSD and its
frequent co-morbidities: depression and the substance
use disorders
Psychological Trauma Basics (cont.)
• PTSD is a specific psychiatric disorder that involves:
1. Repeated intrusive recollections of the PTE
2. Avoidance of reminders of the PTE and/or emotional
numbing
3. Symptoms of hyperarousal
• Epidemiologic studies suggest that “human made”
events (i.e., purposeful or intentional violence or
degradation) are more malignant than natural disasters
9/11
9/11 Evidence Base
• Findings from 4 major epidemiologic studies published in
top-tier journals within 12 months
• All used RDD or internet-based methods, and all used
screening instruments to assess PTSD
9/11 Exposures
• Massive, visually spectacular destruction at the WTC
• Major destruction at the Pentagon
• Nearly 3,00 Americans killed
• Intense media coverage of the events and aftermath
(including anniversaries)
9/11 Psychosocial Outcomes
• Prevalence of probable PTSD associated with attacks in
first 1–2 months in New York 7.5%–11.2%
• Prevalence of probable PTSD in New York fell to about
3% at 4 months post and about 1% at 6–9 months post
• Prevalence of depression in New York 9.7%–14.2%
• More than 10 million Americans reported a relative or
close friend killed
9/11: What did we learn?
• Although mass disasters can create large numbers of
cases of PTSD, the vast majority are self-limiting.
• A person does not have to be on-the-scene of a largescale PTE to be affected by it.
• TV coverage may play some role in outcomes.
Hurricane Katrina
Hurricane Katrina Evidence Base
• At present, virtually no empirical data base on specific
trauma exposures or psychosocial impact (no peerreviewed publications)
• Primary source of information at present remains the
“grey” literature—e.g., articles in newspapers, magazines,
and other media outlets
Hurricane Katrina Exposures: Overview
• Unusually high winds and heavy rain produce extensive
flooding, resulting in many deaths and unprecedented
property loss (homes, possessions)
• Widespread job loss resulting from infrastructure damage
• Some interpersonal violence?
• Massive relocation, often very far away (e.g., Denver, Salt
Lake City, Boston), of people who had “lost everything”
• Widespread loss of social and other support systems
• Widespread uncertainty about the future
Hurricane Katrina Trauma Exposures: Those
Who Stayed
• The more than 150,000 people who rode out the storm in
New Orleans or along the Gulf Coast were exposed to
very high winds, torrential rains, and storm surge as high
as 30 feet.
• In New Orleans, the confluence of these three factors
caused breaches in protective levees that produced
widespread, unusually rapid flooding. About 80% of New
Orleans flooded, with water depths exceeding 20 feet in
some areas.
Hurricane Katrina Trauma Exposures: Those
Who Stayed (cont.)
• Violence and looting were documented in New Orleans in
the aftermath of the storm, including at the Superdome
• More than 1,000 died in New Orleans, others still
classified as “missing”
• More than $34 billion in property damage across the Gulf
coast, including $22 billion in Louisiana
Hurricane Katrina Trauma Exposures: Those
Who Evacuated in Advance
• The late start and slow pace of evacuation was a source
of anxiety, irritation, and/or anger for many evacuees.
• Some of those who evacuated did not initially go far
enough inland to avoid the storm’s effects, and were
therefore subjected to many of the storm’s exposures
(e.g., high winds, flooding, additional evacuation).
• Evacuation did not protect homes and other property left
behind, most of which was damaged or destroyed by
flooding.
Hurricane Katrina Trauma Exposures: Those
Who Did Both
• Many of those who rode out the storm in New Orleans were
evacuated after the storm passed because of the massive
infrastructure damage in New Orleans.
• A month after the storm hit, more than 800,000 New Orleans residents
were still displaced, and they were dispersed widely across the U.S.
• The New Orleans school system was decimated (buildings destroyed,
teachers evacuated and have not returned). As a result, few children
who returned to NO attended school this year
• Similarly, estimates suggest that ~20% of children evacuated did not
enroll in schools or enrolled but did not attend schools in the areas to
which their families relocated
Hurricane Katrina Trauma Psychosocial
Outcomes
• Telephone survey random sample (n=1,510) of those who
had contacted Red Cross in the first month after Katrina
found that 7% reported being injured during the storm,
and 8% reported being a victim of a crime during or
immediately after the storm. Half reported being separated
from family members for at least one day, and 20%
reported losing a pet.
• Telephone survey of a random sample selected from list of
more than 160,000 Katrina evacuees 7–8 months after the
storm found that African-American evacuees were more
likely than whites to report that: they had been separated
from family members by the storm, that their former
homes had been destroyed, and that a relative or close
friend died in the storm.
Hurricane Katrina Trauma Psychosocial
Outcomes (cont.)
• Personal interviews conducted in New Orleans by CDC in
the second month after the storm with people who had
returned found:
– 46% of participants reporting that their homes had “very
much” damage;
– 52% describing their homes as “not safe;”
– 67% had no electricity, no gas, telephone service, no
garbage removal, and more than half reported no running
water and no working toilet; and
– 33% reported problems obtaining medical care.
What We Know from Studies of Other Disasters
• Post-exposure mental health symptom levels are related
to sociodemographic characteristics:
– Gender (females are more symptomatic)
– Age (younger people are more symptomatic)
– Prior trauma exposure (more symptomatic)
– Prior psychiatric disorder (more symptomatic)
What We Know from Studies of Other Disasters
(cont.)
• Post-exposure mental health symptom levels are related
to sociodemographic characteristics:
– Socioeconomic status (lower more symptomatic)
– Post-exposure social support (lower more symptomatic)
– Resource losses (more losses more symptomatic)
What Have We Learned from Katrina?
• A disaster that includes both widespread psychological trauma and
massive infrastructure damage that cannot be quickly repaired or
replaced creates challenges that are much more complicated than
when infrastructure damage is minimal
• Although from the historical perspective such events are rare, it is
clear that better preparedness would have reduced substantially the
psychosocial impact of Katrina
• We will soon begin to see empirical findings of the psychological
aftermath. Many expect that Katrina’s impact on adults will be much
more extensive than prior hurricanes, and that its impact on the lives
of exposed children will prove to be pervasive
• Experience with Katrina raises fundamental preparedness questions
about our ability to respond to events that, in addition to threatening
lives, also create extensive infrastructure damage (e.g., intense
hurricanes or earthquakes)
High Priority Research Questions
• How can we distinguish in the immediate aftermath of a
major disaster between those who are at highest risk for
developing chronic PTSD versus those whose PTSD will
be self-limiting, so that we can triage them appropriately?
• In disasters that produce major infrastructure damage,
how can we best:
– establish the capacity to provide treatment to those who
need it (i.e., how do we arrange for an adequate number of
providers), and
– assure that professional treatment goes to those who most
need it (i.e., how do we optimally allocate the treatment
resources that are available)?