The Effects of Natural Disasters
A National Center for PTSD Fact Sheet
Prepared by: Fran H. Norris, Ph.D.
The
psychosocial consequences of natural disasters have been studied extensively.
When Norris and colleagues (2002) reviewed this literature, they found
a wide range of effects. About a third of these studies found effects
that were quite severe, meaning that a high percentage of study participants
exhibited clinically significant distress or diagnosable disorders. The
most frequently reported condition was PTSD, followed by depression,
and then other anxiety disorders. Many survivors also reported nonspecific
distress, health problems, chronic problems in living, and resource loss.
Within the adult samples, risk factors for adverse outcomes included
more severe exposure, female gender, middle age, ethnic minority group membership,
secondary stress, prior psychiatric problems, and weak or deteriorating
psychosocial resources. Consistent support has been found for the importance
of coping self-efficacy in predicting psychological outcomes from a variety
of disasters, including but not limited to hurricanes (Benight & Bandura,
2004).
In
some of these studies, participants were interviewed more than once so
that the disaster's effects could be studied over time. Most often, people
improved as time passed. However, almost all studies included a minority
of participants who did not improve but, for whatever reason, continued
to be distressed or impaired long after the event. As the authors of these
studies often remarked, these particular people who do not recover on their
own are especially important to understand and serve.
Quite
a few studies have been conducted specifically on the effects of hurricanes,
including such major events as Hurricane Hugo, Hurricane Andrew, and Hurricane
Mitch. Norris and colleagues (2002) described Hurricane Andrew as a good
example of a "high impact disaster." In one study of 400 highly exposed
residents of southern Dade County, 25% of the sample met study criteria
for PTSD 6 months after the hurricane. Symptoms of depression and avoidance
remained high as late as 30 months after the hurricane struck (Norris et
al., 1999). Lasting symptoms were especially likely when people experienced
other forms of life stress in addition to the hurricane or had poor self-esteem
or weak social ties. Long after Hurricane Andrew, many people felt less
positive about the quality of their social relationships than they had
felt before the disaster (Norris & Kaniasty, 1996), suggesting that
perceptions of social support are also harmed by disaster experience.
In
this study, the effects of Hurricane Andrew appeared to be more severe
for Latinos, especially less acculturated Latinos, than for non-Hispanic
Whites and Blacks (Perilla and colleagues, 2002). To a degree, this finding
was explained by Latinos' greater exposure, but it was also partially explained
by Latinos' higher levels of fatalism (external control) and acculturative
stress (discomfort in dealing with members of other ethnic groups). The
mediating role of fatalism is consistent with a large literature showing
that low perceived control is a risk factor for poor psychological outcomes.
Acculturative stress might have hindered help-seeking or exacerbated the
effects of other stressors.
Altogether,
the evidence from this study of Hurricane Andrew, as well as from other
disaster studies, suggests that the long-term emotional consequences of
disaster follow strongly from survivors' thoughts or beliefs. Adults at
risk for mental health problems think that they (a) are uncared for by
others, (b) have little control over what happens to them, or (c) lack
the capacity to manage stress.
These hurricane-specific findings
are consistent with findings from research on other forms of trauma that
have examined the factors predicting whether or not a person develops chronic
PTSD. Two of the strongest factors influencing recovery are subsequent
life stress and social support from others. The most recent research
with survivors of assaults and motor vehicle accidents has consistently
shown that the presence of negative social support impedes recovery (Dunmore,
Clark, & Ehlers, 2001; Ullman & Filipas, 2001; Zoellner, Foa, & Brigidi,
1999). Family members' critical comments about the length of time taken
for recovery seem to stand in the way of trauma victims' recovery in treatment
for PTSD.
Related Web Resources
Range, Magnitude, and Duration of the Effects of
Disasters on Mental Health: Review Update 2005
by Fran H. Norris
Dartmouth Medical School and National Center for PTSD
More detailed information on the mental health impact of disasters is found in this article which is
posted on the Research Education in Disaster Mental Health (REDMH) Web site.
