What causes Posttraumatic Stress Disorder? How common is it?
Who gets it?
These questions are asked by epidemiologists, and two major
epidemiological studies have produced some answers.
Several studies have been conducted in the history of the US to examine how prevalent PTSD is in the general population or in special populations. The National
Vietnam Veterans Readjustment Survey (NVVRS), conducted between
November 1986 and February 1988, comprised interviews of 3,016
American veterans selected to provide a representative sample of
those who served in the armed forces during the Vietnam era. The
National Comorbidity Survey (NCS), conducted between September
1990 and February 1992, comprised interviews of a representative
national sample of 8,098 Americans aged 15 to 54 years. The most recent National Comorbidity Survey Report, published in 2005 on a newer sample, estimated lifetime prevalence of PTSD among adult
Americans at 6.8%.
The earlier NCS data set estimated prevalence of lifetime PTSD to be 7.8% in the general adult
population, with women (10.4%) twice as likely as men (5%)
to have PTSD at some point in their lives. This represents a
small portion of those who have experienced at least one
traumatic event; 60.7% of men and 51.2% of women reported at
least one traumatic event. The most frequently experienced
traumas were:
Witnessing someone being badly injured or killed
Being involved in a fire, flood, or natural disaster
Being involved in a life-threatening accident
Combat exposure
The majority of the people in the NCS experienced two or more
types of trauma. More than 10% of men and 6% of women reported
four or more types of trauma during their lifetimes.
The traumatic events most often associated with PTSD in men
were rape, combat exposure, childhood neglect, and childhood
physical abuse. For women, the most common events were rape,
sexual molestation, physical attack, being threatened with a
weapon, and childhood physical abuse.
However, none of these events invariably produced PTSD in
those exposed to it, and a particular type of traumatic event did
not necessarily affect different sectors of the population in the
same way.
The NCS report concluded that "PTSD is a highly prevalent
lifetime disorder that often persists for years. The qualifying
events for PTSD are also common, with many respondents reporting
the occurrence of quite a few such events during their
lifetimes."
The National Vietnam Veterans Readjustment Survey (NVVRS)
The NVVRS report provided the following information about
Vietnam War veterans:
PTSD
The estimated lifetime prevalence of PTSD among American
Vietnam theater veterans is 30.9% for men and 26.9% for women. An
additional 22.5% of men and 21.2% of women have had partial PTSD
at some point in their lives. Thus, more than half of all male
Vietnam veterans and almost half of all female Vietnam veterans
-about 1,700,000 Vietnam veterans in all- have experienced
"clinically serious stress reaction symptoms."
15.2% of all male Vietnam theater veterans (479,000 out of
3,140,000 men who served in Vietnam) and 8.1% of all female
Vietnam theater veterans (610 out of 7,200 women who served in
Vietnam) are currently diagnosed with PTSD ("Currently" means
1986-88 when the survey was conducted).
Other
problems of Vietnam veterans
Forty percent of Vietnam theater veteran men have been
divorced at least once (10% had two or more divorces), 14.1%
report high levels of marital problems, and 23.1% have high
levels of parenting problems.
Almost half of all male Vietnam theater veterans currently
suffering from PTSD had been arrested or in jail at least once
-34.2% more than once- and 11.5% had been convicted of a
felony.
The estimated lifetime prevalence of alcohol abuse or
dependence among male theater veterans is 39.2%, and the estimate
for current alcohol abuse or dependence is 11.2%. The estimated
lifetime prevalence of drug abuse or dependence among male
theater veterans is 5.7%, and the estimate for current drug abuse
or dependence is 1.8%.
Because the NVVRS sample size underrepresented members of
certain ethnic minorities, the Matsunaga Vietnam Veterans Project
undertook further epidemiological research among Native American,
Asian American, and Pacific Islander veterans. These findings are
summarized in two separate National Center for PTSD fact sheets.
This Fact Sheet Was Based On:
Richard A. Kulka et al.,
Trauma and the Vietnam War Generation: Report of Findings from
the National Vietnam Veterans Readjustment Study (New York:
Brunner/Mazel, 1990; ISBN 0-87630-573-7)
Ronald C. Kessler et al.,
Posttraumatic Stress Disorder in the National Comorbidity
Survey Archives of General Psychiatry, 52(12), 1048-1060
(December 1995)
