Child Development And Post-traumatic Stress Disorder After Hurricane Exposure
Alan M. Delamater, PhD, and E. Brooks Applegate, PhD
University of Miami School of Medicine
Abstract
This study examined child development in relation to post-traumatic stress disorder (PTSD) after
hurricane exposure. The study subjects were 175 3 to 5-year old minority children enrolled in Head
Start programs. Children were evaluated 12 and 18 months after Hurricane Andrew struck south
Florida. Mothers were interviewed concerning symptoms of PTSD and completed a questionnaire
regarding their children’s development. Results indicated that 16.5% of exposed children met
DSM-IV diagnostic criteria for PTSD at 12 months, and 11.6% had PTSD at 18 months
post-hurricane. Children who had PTSD at 12 months were more likely to be delayed in their
development at 18 months, and those with PTSD at 18 months similarly were more likely to be
delayed. These findings indicate that children with PTSD are at risk for delays in their overall
development.
Post-traumatic Stress Disorder and Development of Children after Hurricane Exposure
Natural disasters often result in destruction of property, major economic losses for affected
communities, serious injuries, and loss of life. The psychological toll of natural disasters is also quite
significant. Studies with children indicate increases in psychological problems following natural
disasters such as lightning strikes (Dollinger, O’Donell, & Stanely, 1984)), tornados (Bloch, Silber,
& Perry, 1956)), floods (Burke, Borus, Burns, Millstein, & Beasley, 1982; Earls, Smith, Reich, &
Jung, 1988; Gleser, Green, & Winget, 1981; Newman, 1976), earthquakes (Galante & Foa, 1986),
bushfire (McFarlane, 1987), and hurricanes (La Greca, Silverman, Vernberg, & Prinstein, 1996;
Shaw, Applegate, Tanner, Perez, Rothe, Campo-Bowen, & Lahey, 1995; Vernberg, La Greca,
Silverman, & Prinstein, 1996). However, there is limited controlled epidemiological data available on
psychological morbidity of children following exposure to major disasters (Pefferbaum, 1997;
Shannon, Lonigan, Finch, Taylor, & Sallie, 1994; Vogel & Vernberg, 1993).
A number of psychological symptoms have been observed in children following disasters, including
fears, sleep problems, depression, separation anxiety, somatic complaints, and conduct problems.
More recently, as the concept of post-traumatic stress disorder (PTSD) has been applied to
children, studies have found symptoms of PTSD in children following natural disasters (Lonigan,
Shannon, Finch, Daugherty, &Taylor, 1991; Pefferbaum, 1997; Vogel & Vernberg, 1993). For
example, recent studies have shown a high rate of PTSD symptoms in school-age children following
exposure to a severe hurricane (La Greca, Silverman, Vernberg, & Prinstein, 1996; Vernberg, La
Greca, Silverman, & Prinstein, 1996). There is also evidence of PTSD among children exposed to
other types of severe trauma such as sniper attack (Pynoos, Frederick, Nader, Arroyo, Steinberg,
Eth, Nunez, & Fairbanks, 1987)), kidnapping (Terr, 1983), witnessing violence (Kinzie, Sack,
Angell, Manson, & Rath, 1986; Saigh, 1989), and sexual abuse (Kiser, Ackerman, Brown,
Edwards, McColgan, Pugh, & Pruitt, 1988). Available studies of children suggest that symptoms of
PTSD are related to degree of exposure to life threat (Pynoos et al., 1987) and levels of parental
distress (McFarlane, 1987), and may persist for long periods after the disaster (Galante & Foa,
1986; Kinzie et al., 1986; Terr, 1983).
The homelessness and dislocation secondary to property damage from a major disaster interrupts
peer friendship patterns. The loss of social support may result in isolation and increases in
dependency upon adults. Post-traumatic stress reactions may exacerbate this situation so that
children's progression through social, cognitive, and emotional developmental tasks may be
obstructed. The effects of major stress on general child development have not been adequately
investigated (Pynoos & Nader, 1989), although clinical reports suggest severe stress may result in
personality changes even in young children (Terr, 1979). Basic information is also needed concerning
developmental effects in children's response to natural disaster. Some studies have reported no age
effects after major trauma (Burke et al., 1982; Pynoos et al., 1987), while others indicate older
school-age children have more symptoms than younger preschool-age children (Gleser, Green, &
Winget, 1981; Handford, Mayes, Mattison, Humphrey, Bagnato, Bixler, & Kales, 1986). A number
of clinical studies indicate that preschool-age children display PTSD after witnessing violent acts (Eth
& Pynoos, 1985; Schetky, 1978; Zeanah & Burke, 1984). However, little is known about
preschool-age children's psychological responses to natural disaster, and few studies have examined
the role that socioeconomic and cultural factors may play.
Thus, while studies have shown symptoms of PTSD may occur in school-age children following
exposure to natural disasters and other major stress involving life threat, little is known about PTSD
in younger, pre-school aged children, and how PTSD may affect their overall development.
Therefore, the purpose of this study was to determine the effects of PTSD on child development in a
sample of low income, preschool-aged children, exposed to Hurricane Andrew in south Florida
during August, 1992. We hypothesized that PTSD would have deleterious effects on children’s
attainment of developmental skills.
Method
Participants
The subjects for this study were 175 children (ages 3-5 years) enrolled in Head Start programs of
Miami-Dade County. All of the children were from socio-economically disadvantaged families, in
accordance with eligibility criteria for Head Start. Families were recruited from two Head Start
programs in the south part of the county, which was where the hurricane hit, and two programs from
the north part of the county, approximately 40 miles away from where the eye of the hurricane
passed. The south (n=101) and north (n=74) samples were similar in terms of age (4.4 vs. 4.3
years), gender (45% vs. 48% male), and marital status (63% vs. 64% single). However, there were
differences (p<.001) in race/ethnicity, with the southern sample being 14% white, non-Hispanic,
42% Hispanic, and 43% black, while the northern sample was 1% white, non-Hispanic, 25%
Hispanic, and 74% black. In addition, the highest grade completed by mothers in the south was
lower than in the north sample (11.7 vs. 12.5, p<.02).
Measures
The measures for this study included assessment of demographic variables, symptoms of PTSD in
children, and overall child development.
Demographic Variables. Demographic variables included age, gender, racial/ethnic status, marital
status, and highest grade completed by mothers. This information was obtained by interview with the
mother.
Symptoms of PTSD. The child was assessed for PTSD using the methodology developed by
Pynoos and colleagues, the Child PTSD Reaction Index (Nader, Pynoos, Fairbanks, & Frederick,
1990; Nader, Stuber, & Pynoos, 1991; Pynoos et al., 1987; Stuber, Nader, Yasuda, Pynoos, &
Cohen, 1991). Parents were interviewed concerning the symptoms their child has shown since the
stressful event. All of the 17 symptoms listed in the DSM-IV for PTSD are included in this measure
in addition to other symptoms young children may exhibit after exposure to significant stress. Parents
were asked to indicate whether or not their child was currently exhibiting each of the symptoms since
the time of the hurricane. A diagnosis of PTSD was made on the basis of data obtained from this
assessment procedure, using the 17 items included in the DSM-IV criteria. The Child PTSD
Reaction Index has been shown to have acceptable reliability and vailidity (Nader et al., 1990,
1991; Pynoos et al., 1987; Stuber et al., 1991).
Child Development. General child development was measured by the Preschool Development
Inventory (PDI), a 60-item scale based on parental report (Ireton, 1981). Each of the items in this
screening inventory represents a developmental task that the parent indicates the child has either
succeeded with or not. The items cover language comprehension, expressive language, fine and
gross motor skills, self-help skills, personal-social skills, and comprehension of situations. The
number of items the child has not passed is compared with norms for their age to determine whether
or not they exhibit a developmental delay, defined as 25% below age cutoff scores. A child would
be considered to be possibly delayed if he or she obtained a score that was lower than the average
score for children who are 25% younger. The PDI has adequate psychometric properties and is well
normed for children in the age range of 3-6 years (Ireton, 1988).
Procedure
Families were recruited to the study by a research assistant who met with parents as they dropped
off or picked up their children at the Head Start Center. After the parents (in almost all cases,
mothers) were told about the study, and their questions answered, they completed informed consent
according to a protocol approved by the Institutional Review Board for the Protection of Human
Subjects.
Mothers were interviewed on two occasions: the first time occurred between nine and 15 months
post-hurricane, and the second was in the interval of 15 to 21 months post-hurricane. The average
time since the hurricane for the first and second assessments was 12 and 18 months, for the study
sample as a whole. Mothers were given $10 as an incentive for participation in each of the two
assessments, which were held at the Head Start Center. The second measure of child PTSD was
obtained for 153 (87.4%) of the original 175 children in the study sample, and the second measure
of child development was obtained for 163 (93.1%) of the original study sample.
Results
PTSD in Children
At 12 months post hurricane, more symptoms of PTSD were reported by mothers in the
hurricane-exposed southern sample than in the northern sample (6.7 vs. 3.9, t(174) = 5.19,
p<.0001). Similarly, at 18 months post-hurricane, children in the south still exhibited more PTSD
symptoms (6.0 vs. 3.8, t(148) = 5.19, p<.0001).
Mothers’ responses from the Child PTSD Reaction Index were also utilized to categorize children
into two groups: those with PTSD vs. those not having enough symptoms to meet DSM-IV
diagnostic criteria. At 12 months post-hurricane, 16.5% of the southern sample vs. 4.0% of the
northern sample had PTSD (chi-square (1) = 6.55, p<.01). At 18 months post-hurricane, 11.6% of
children in the south had PTSD, vs. 3.1% in the north (chi-square (1) = 3.60, p<.058).
More data concerning children’s psychological responses and PTSD symptoms are detailed in a
separate report, including various exposure-related, demographic, and psychosocial predictors of
PTSD (Delamater, Applegate, Kerdyk, & Shaw, 1999). For the present study, we report only the
overall findings concerning PTSD as it relates to the primary outcome variable, child development.
Child Development
At 12 months post-hurricane, 30.9% of the entire study sample were rated as being delayed in their
overall development. There was a marginal effect (chi-square (1) = 2.93, p<.087) for the south vs.
north site effect, with 31.2% in the south and 22.8% of children in the north rated as delayed. At 18
months post-hurricane, 15.3% of the children were rated as delayed, but there was no effect of site
(14.3 vs. 10.7% in the south vs. north).
PTSD and Child Development
There was no relationship between PTSD diagnostic status and developmental delay at 12 months
post-hurricane. However, there was a significant relationship between PTSD status at 12 months
and developmental delay at 18 months (chi square (1) = 8.64, p<.003): children with PTSD at 12
months were more likely to be developmentally delayed at 18 months post-hurricane than those
without PTSD (Odds Ratio = 4.5, 95% confidence intervals, 1.7 to 12.3). Similarly, there was a
significant relationship between PTSD status at 18 months and developmental delay at 18 months
(chi square (1) = 6.48, p<.01): children with PTSD at 18 months were more likely to be
developmentally delayed at 18 months post-hurricane than those without PTSD (Odds Ratio = 7.9,
95% confidence intervals, 1.6 to 38.7).
Discussion
These findings demonstrate that young preschool-age children who were exposed to the stress of a
major hurricane were more likely to exhibit symptoms of PTSD than a comparison group of children
who were less exposed to life threat by being geographically removed from the most damaging
winds of the storm. Even one year after experiencing the hurricane, PTSD symptoms were fairly
common and 16.5% of exposed children met diagnostic criteria for PTSD on the basis of their
mothers’ reports. At eighteen months post-hurricane, 11.6% of children who lived in the south part
of the county where the hurricane did the most damage, still met criteria for PTSD. It is noteworthy
that a small percentage of children living in the less exposed, northern part of the county met
diagnostic criteria for PTSD, and many children exhibited some symptoms, although less than the
more exposed children. This attests to the fact that the entire county was under threat of the
hurricane, and even in the north, very high winds and some damage was experienced, and the
disruption associated with the aftermath was felt throughout the entire county. While this study is one
of the first to examine PTSD in preschool age children after exposure to a natural disaster, it is
consistent with studies suggesting PTSD may occur in children of this age who have witnessed
violent acts (Eth & Pynoos, 1985; Schetky, 1978; Zeanah & Burke, 1984).
A significant percentage of children were rated by their mothers as having delays in their overall
development: 31% at 12 months post-hurricane and 15% at 18 months post-hurricane. While these
numbers seem fairly high, they may not be elevated for the population of children attending Head
Start programs, who are more likely to be from minority, single-parent families experiencing a variety
of economic and social stressors. Children growing up in such stressful environments may be at risk
for some delays in their development.
This study is among the first to examine the effects of PTSD on the general development of young
children. The finding that the presence of PTSD was associated with delays in overall development
of children supports the primary hypothesis of the study. In fact, children with PTSD at 12 months
post-hurricane were four and a half times more likely to have developmental delays at 18 months
post-hurricane than children without PTSD, and those with PTSD at 18 months post-hurricane were
nearly eight times more likely to continue to have significant delays in general development. These
findings indicate that besides the distressing symptoms of PTSD for children and their families, the
child with PTSD is also at risk for more general delays in their overall cognitive, social, emotional,
and physical development, supporting previous clinical reports that severe stress can have debilitating
consequences for the personality development of young children (Terr, 1979).
Assessment of PTSD in young children can be challenging, as subjective experience is important to
consider in making the diagnosis. With very young children, as in the current study, it is necessary to
interview parents to determine the presence of symptoms of PTSD. The Child PTSD Reaction Index
has previously been used to ascertain the presence of clinically significant symptoms of PTSD, in
direct interviews of children. With preschool-age children as the focus of our study, we utilized the
items of the Reaction Index in a structured interview with the mothers. In the present report, we
utilized only the 17 items included in the DSM-IV diagnostic criteria for PTSD in our analyses. As
part of our overall study, we also interviewed children directly using the Child PTSD Reaction Index.
However, the question of the relationship between child and parent reports of PTSD symptoms is
beyond the scope of the current report.
This study has some limitations. First, the measurement of both PTSD and general development
were made by mothers. As these were self-report measures by structured interview and
questionnaire, they may be subject to bias related to their own recall and/or their own levels of
distress related to the hurricane and its aftermath. Further studies could benefit by inclusion of more
than one type of informant, e.g., by including children’s self-reports, teachers, or other adults who
know the children well. While the finding of a relationship between PTSD and developmental delay
is important, it would be informative to know more specifically about the nature of the delays,
whether for example, they are in social, emotional, and/or cognitive areas. The measure utilized in the
current study provided only an overall indicator of general development, rather than more precise
measurement of specific areas of child development. In addition, while this study was limited by not
having pre-hurricane data on the emotional and developmental functioning of the children, the use of
a comparison group of demographically similar children did provide some control and lend
confidence to the findings. Finally, the lack of data during the initial nine to twelve months
post-hurricane may be considered a limiting feature of the study design. Nevertheless, the fact that
PTSD and its developmental consequences were observed for up to eighteen to twenty-one months
after hurricane exposure provides important data concerning the time course and persistence of
emotional and developmental effects in young children.
These findings have implications for the caregivers of young children. Because having PTSD may
place young children at risk for developmental delays, parents and other caregivers of
preschool-aged children should make sure that developmentally stimulating activities are routinely
provided to traumatized children after exposure to natural disaster. Developmental status should be
formally evaluated in children when parents or other caregivers express concerns about their
attainment of expected developmental skills.
In summary, this study has shown that young preschool-age children commonly exhibit symptoms of
PTSD after exposure to a life-threatening hurricane, with 16.5% of exposed children meeting
diagnostic criteria for PTSD by mother report one year after the hurricane, and 11.6% continuing to
have PTSD eighteen months after the hurricane. These findings indicate the presence of PTSD
places young children at increased risk for failure to achieve normal development in cognitive, social,
and emotional skills. Further studies are needed to specify how PTSD may interfere with normal
child development.
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Author Note
Appreciation is expressed to Esly Valdeon and Elizabeth Balbin, who contributed to the data
collection and data management phases of the study, and to Abilio Rodriquez, Director of Mental
Health Services at Miami-Dade Head Start, for facilitating recruitment of Head Start Centers for the
study.
This grant was supported by grant #MH51483 from the National Institutes of Mental Health.
Correspondence concerning this article should be directed to Alan M. Delamater, Ph.D., Mailman
Center for Child Development (D-820), P.O. Box 016820, University of Miami School of
Medicine, Miami, FL 33101, or via Internet to adelamat@peds.med.miami.edu.
_______________________________________________________________________________________________________________
Alan M. Delamater, Ph.D.
E. Brooks Applegate, Ph.D.
University of Miami School of Medicine
Email: adelamat@peds.med.miami.edu
