Psychological Medicine (2016), 46, 771–783.

© Cambridge University Press 2015 OR I G I N A L A R T I C L E

doi:10.1017/S0033291715002184

DSM-IV post-traumatic stress disorder among World

Trade Center responders 11–13 years after the
disaster of 11 September 2001 (9/11)

E. J. Bromet1*, M. J. Hobbs1, S. A. P. Clouston2, A. Gonzalez1, R. Kotov1 and B. J. Luft3

1
Department of Psychiatry, Putnam Hall-South Campus, Stony Brook University, Stony Brook, NY, USA
2
Program in Public Health and Department of Preventive Medicine, Stony Brook University, Stony Brook, NY, USA
3
Department of Medicine, Stony Brook University, Stony Brook, NY, USA

Background. Post-traumatic symptomatology is one of the signature effects of the pernicious exposures endured by
responders to the World Trade Center (WTC) disaster of 11 September 2001 (9/11), but the long-term extent of diagnosed
Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) post-traumatic stress disorder (PTSD) and
its impact on quality of life are unknown. This study examines the extent of DSM-IV PTSD 11–13 years after the disaster
in WTC responders, its symptom profiles and trajectories, and associations of active, remitted and partial PTSD with
exposures, physical health and psychosocial well-being.

Method. Master’s-level psychologists administered sections of the Structured Clinical Interview for DSM-IV and the
Range of Impaired Functioning Tool to 3231 responders monitored at the Stony Brook University World Trade
Center Health Program. The PTSD Checklist (PCL) and current medical symptoms were obtained at each visit.

Results. In all, 9.7% had current, 7.9% remitted, and 5.9% partial WTC-PTSD. Among those with active PTSD, avoidance
and hyperarousal symptoms were most commonly, and flashbacks least commonly, reported. Trajectories of symptom
severity across monitoring visits showed a modestly increasing slope for active and decelerating slope for remitted PTSD.
WTC exposures, especially death and human remains, were strongly associated with PTSD. After adjusting for exposure
and critical risk factors, including hazardous drinking and co-morbid depression, PTSD was strongly associated with
health and well-being, especially dissatisfaction with life.

Conclusions. This is the first study to demonstrate the extent and correlates of long-term DSM-IV PTSD among respon-
ders. Although most proved resilient, there remains a sizable subgroup in need of continued treatment in the second
decade after 9/11.

Received 20 July 2015; Revised 22 September 2015; Accepted 22 September 2015; First published online 25 November 2015

Key words: 9/11, Disaster responders, exposure, post-traumatic stress disorder, psychosocial well-being, World Trade
Center.

Introduction electricians, and transportation and utility workers

(Dasaro et al. 2015). In the aftermath of the attacks,
Responders to the World Trade Center (WTC) disaster
two programs were established to monitor responders’
of 11 September 2001 (9/11), particularly the men and
health and treat WTC-related conditions, one for police
women who were at the site on 11 September, were
and non-traditional responders (World Trade Center
exposed to emotionally horrifying events and environ-
Health Program; WTCHP) and one for New York
mental toxins from multiple gases and fine airborne
City firefighters. In addition, the New York City
particulate matter from the collapse of the towers.
Department of Health established the WTC Health
The responders who participated in the rescue, recov-
Registry to track the health and well-being of indivi-
ery and clean-up operations included experienced
duals directly exposed to the collapse of the towers
workers with extensive training, such as police and
or its immediate aftermath.
firefighters, and non-traditional responders with no
All three programs obtained serial data on post-
disaster training, such as construction workers,
traumatic stress symptoms from the PTSD Checklist
(PCL) (Blanchard et al. 1996). During the first decade
after 9/11, 5–23% of responders had PCL scores sug-
* Address for correspondence: E. J. Bromet, Ph.D., Department of
Psychiatry, Putnam Hall-South Campus, Stony Brook University,
gestive of possible post-traumatic stress disorder
Stony Brook, NY 11794-8790, USA. (PTSD) (Liu et al. 2014), with higher rates among non-
(Email: evelyn.bromet@stonybrookmedicine.edu) traditional compared with professional responders
This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://
creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium,
provided the original work is properly cited.
772 E. J. Bromet et al.

(Perrin et al. 2007; Ozbay et al. 2013). Trajectory ana- that partial PTSD, defined as meeting cluster B and
lyses for responders who made three monitoring visits either cluster C or D criteria, decreased from 17.9% to
to the WTCHP found that 5.3% of police and 9.5% of 7.7%. The third study administered the Diagnostic
non-traditional responders had chronically elevated Interview Schedule to a large sample of retired
symptoms, and 8.4% and 12.4%, respectively, experi- firefighters in 2006–2007; 6.5% had current DSM-IV
enced a reduction in symptom severity (Pietrzak et al. PTSD (Chiu et al. 2011). Thus, no study assessed
2014). A recent analysis of responders in the WTC WTC-related DSM-IV PTSD in police, who were crit-
Health Registry found that half of police responders ical first responders on 9/11, or in heterogeneous sam-
with probable PTSD in the first few years after 9/11 ples of non-traditional rescue/recovery workers, who
continued to have probable PTSD at 10–11 year follow- had no training in disaster response. We also lack ad-
up (Cone et al. 2015). equate information on the clinical profiles of respon-
WTC exposures, particularly being in the dust cloud ders with DSM-IV PTSD and the relative effects of
and death of colleagues, were significantly associated persistent and remitted PTSD on health and psycho-
with self-report PTSD symptoms (e.g. Perrin et al. social well-being.
2007; Yip et al. 2015) independent of demographic To fill these gaps, we assessed a large cohort of
and other risk factors (Friedman et al. 2013). In add- WTCHP police and non-traditional responders in
ition, consistent with the broader literature (O’Toole 2012–2014 with the Structured Clinical Interview for
& Catts, 2008; McFarlane, 2010; Pacella et al. 2013), DSM-IV (SCID; First et al. 1996) and the Range of
PTSD symptom severity was significantly associated Impaired Functioning Tool (RIFT) (Leon et al. 1999)
with responders’ physical health, particularly respira- in order to examine: (1) the percentage of responders
tory symptoms, a hallmark medical outcome of WTC developing WTC-PTSD; (2) the criterion symptoms
exposures (Webber et al. 2011; Wisnivesky et al. 2011; most frequently endorsed by active cases; (3) the com-
Luft et al. 2012; Nair et al. 2012; Friedman et al. 2013; parative course of PCL symptoms for responders with
Pietrzak et al. 2014; Cone et al. 2015; Kotov et al. active, remitted, partial and no WTC-PTSD; (4) the
2015). The temporal order has not been firmly estab- effects of physical and psychological exposures on
lished, but recent evidence suggests that PTSD symp- long-term WTC-PTSD; and (5) associations of active,
toms drive the relationship rather than the converse remitted and partial WTC-PTSD with current health
(Kotov et al. 2015). Far fewer WTC responder studies and psychosocial well-being.
have addressed the relationships of PTSD symptoms
with psychosocial well-being (e.g. Stellman et al.
2008; Schwarzer et al. 2014) even though PTSD symp- Method
toms are an impediment to quality of life (Koenen
Setting
et al. 2008) and increase the risk of depression
(Breslau et al. 2000; Stander et al. 2014). The sample was derived from the Long Island/Stony
All of the studies described above are based on a Brook University WTCHP, the second largest of five
probable diagnosis of PTSD from the PCL. In contrast, Clinical Centers of Excellence in the New York metro-
most other research on trauma established the diagno- politan area (Dasaro et al. 2015). Enrollees with docu-
sis of PTSD from structured or semi-structured diag- mented WTC experience were enlisted from extensive
nostic interviews. Indeed, a longitudinal study of outreach efforts involving partnerships with volunteer
returning National Guard soldiers found that the best organizations, labor unions and public outlets.
PCL cut-scores produced 65–76% false-positive errors The protocol and consent form for the current study
in relation to a Diagnostic and Statistical Manual of were approved annually by the Committees on
Mental Disorders, 4th edition (DSM-IV) PTSD diagno- Research Involving Human Subjects at Stony Brook
sis (Arbisi et al. 2012), and a study of WTC firefighters University. Written informed consent was obtained.
suggested that the cut-points used by WTC investiga- Assessments took place during regularly scheduled
tors may be too high (Chiu et al. 2011). We found monitoring visits between January 2012 and May 2014.
three studies of WTC responders that included a diag-
nostic interview. Two used the Clinician Administered
Participants
PTSD Scale (CAPS; Blake et al. 1995). The first, con-
ducted with mental health relief workers 6–8 months Among the 4587 responders monitored during the
after 9/11, found that 6.4% met criteria for study period, 23 could not be approached due to inad-
WTC-related PTSD (Zimering et al. 2006). The second equate English language skills. Of the remainder, 430
study focused on utility workers and found that declined, 630 did not have time to complete the
PTSD declined from 14.9% in 2002 to 5.8% in 2008 interview, and 3504 participated (76.8% of eligible
(Cukor et al. 2011). Cukor et al. (2011) also reported responders). Their demographic and occupational
 World Trade Center DSM-IV post-traumatic stress disorder 773

Table 1. Characteristics of responders and associations with DSM-IV WTC-PTSD

No diagnosis (n = 2660), n (%) WTC-PTSD (n = 571), n (%) OR (95% CI)

Type of responder
Non-traditional 719 (27.0) 238 (41.7) 1.9 (1.6–2.3)*
Police 1941 (73.0) 333 (58.3) 1.0
Age at 11 September 2001
540 years 1051 (39.5) 230 (40.3) 1.0 (0.9–1.2)
<40 years 1609 (60.5) 341 (59.7) 1.0
Gender
Female 206 (7.7) 74 (13.0) 1.8 (1.3–2.4)*
Male 2454 (92.3) 497 (87.0) 1.0
Educationa
Less than college 1858 (69.8) 419 (73.4) 1.2 (1.0–1.5)
Bachelor’s degree or higher 802 (30.2) 152 (26.6) 1.0
Employment (initial visit)a
Not working 96 (3.7) 83 (14.8) 5.0 (3.7–6.9)*
Retired 281 (10.8) 95 (17.0) 2.0 (1.4–2.6)*
Employed full/part time 2221 (85.5) 381 (68.2) 1.0
Marital status (initial visit)a
Not married 497 (19.0) 140 (25.0) 1.4 (1.1–1.8)*
Married/with partner 2114 (81.0) 421 (75.0) 1.0
Race
Other 572 (21.5) 113 (19.8) 0.9 (0.7–1.1)
Caucasian 2088 (78.5) 458 (80.2) 1.0
Smoking statusa
Current smoker 159 (6.0) 77 (13.7) 2.5 (1.9–3.3)*
Not current smoker 2475 94.0) 484 (86.3) 1.0
Hazardous drinkera
Yes, current 95 (4.3) 72 (14.6) 3.8 (2.8–5.3)*
No 2132 (95.7) 420 (85.4) 1.0
Current major depressiona
Yes 47 (1.8) 218 (38.2) 34.4 (24.6–48.1)*
No 2612 (98.2) 352 (61.8) 1.0
Number of monitoring visits
3+ 1937 (72.8) 422 (73.9) 1.1 (0.86–1.3)
1–2 723 (27.2) 149 (26.1) 1.0
Mental health treatment since 11 September 2001
Yes 628 (23.6) 435 (76.2) 10.4 (8.4–12.8)*
No 2032 (76.4) 136 (23.8) 1.0

DSM-IV, Diagnostic and Statistical Manual of Mental Disorders, 4th edition; WTC, World Trade Center; PTSD, post-
traumatic stress disorder; OR, odds ratio; CI, confidence interval.
a
Missing values.
* p 4 0.001.

characteristics (Table 1) are in line with those of the were modified to assess PTSD symptoms in relation
clinic population as a whole. to traumatic WTC exposures (criterion A). Before con-
ducting the assessment, the interviewers reviewed par-
PTSD ticipants’ occupational and medical histories in order
to facilitate rapport and enhance accurate interpret-
DSM-IV PTSD diagnosis
ation of responses, particularly to physiological items.
Master’s level psychologists were trained to administer Inter-rater agreement for 55 independently rated
the SCID PTSD module without skip-outs (First et al. audiotapes was very good (κ = 0.82).
1996) with interval instructions (worst episode of PTSD diagnoses were considered active if current in
symptoms since 11 September 2001). SCID items the past month, remitted if criteria were met in the past
774 E. J. Bromet et al.

only, and partial if DSM-IV criteria were not met but at General risk factors
least one symptom in the B, C and D clusters was
These included type of responder [police v. non-
endorsed (Breslau et al. 2004).
traditional (primarily construction workers)], age on
9/11 (<40 v. 540 years), gender, education (5bachelor’s
PTSD symptom severity degree v. lower), occupational status at initial monitor-
ing visit (employed full or part time, retired, not work-
As noted, at each monitoring visit, responders com- ing), marital status at initial visit (married/with partner
pleted the PCL-S (specific version) (Blanchard et al. v. separated/divorced/widowed), race (Caucasian;
1996), a 17-item self-report measure modified to assess other), current cigarette smoking (Welch et al. 2015),
symptoms over the past month ‘in relation to 9/11’. current hazardous drinking (58 on the Alcohol Use
Severity is rated on a scale from 1 (not at all) to 5 (ex- Disorders Identification Test; AUDIT-10) (Bohn et al.
tremely). The PCL has good convergent validity and 1995) and current DSM-IV major depressive episode
internal consistency (Wilkins et al. 2011). In the present (assessed with the SCID). Two service use variables
sample, the internal consistency was excellent (α = were also included: number of prior monitoring visits
0.96). Of note, only 58.8% of responders with active and mental health treatment since 9/11 (self-reported
WTC-PTSD had a PCL score indicating possible use of mental health services at either the initial mon-
PTSD (550; Terhakopian et al. 2008). itoring visit or study assessment or filing a psychother-
apy treatment claim with the WTCHP).

WTC exposures
Exposure was systematically assessed at the first mon- Statistical analysis
itoring visit (Dasaro et al. 2015). Six variables were The analyses focused on 3231 Stony Brook responders
included in the analysis: caught in the dust cloud; (92.2% of the sample) with complete information on
early arrival (e.g. on 11 or 12 September; of those arriv- PTSD, dust cloud exposure and loss of colleagues in
ing later, only 84 arrived after 30 September); duration the tower collapse. We calculated the percentage of
of work (519 days in September, which was the top Stony Brook responders who developed PTSD and
quartile, v. fewer days); exposure to human remains; also estimated the rate for the WTCHP general cohort
knowing someone who was injured; and death of col- (n = 33 076) by applying weights (Winship & Radbill,
leagues, friends or family in the tower collapse. A 1994) to adjust for the distribution of males (85.6%),
three-level severity index was created to define no/ Caucasians (56.7%) and police (49%) in the cross-center
low (0–2), intermediate (3–4) and high (5–6) exposure cohort (Dasaro et al. 2015).
levels. In the high exposure category, 98.6% lost a col- Relationships of exposure, health and psychosocial
league or loved one. functioning with PTSD were examined using binomial
and multinomial logistic regression methods. Analyses
were computed with SPSS version 23 (USA).
Health and psychosocial well-being
To examine the trajectories of PTSD symptoms
Health variables were: (1) lower respiratory symptoms among responders with active, remitted, partial and
(cough, wheezing, chest tightness and/or shortness of no DSM-IV PTSD, we used PCL data collected over
breath) assessed by medical staff and categorized as one to nine monitoring visits, with observations occur-
WTC-related if absent before or significantly worse ring on average 1.6 (S.D. = 1.0) years apart. The analyses
following 9/11 and not due exclusively to a cold or incorporated 23 085.8 person-years of observation. We
similar infection (Luft et al. 2012); (2) body mass used exact clinic visit dates to calculate years between
index 535 kg/m2 (e.g. class II obesity or higher) calcu- WTC exposure and observation and years2 to examine
lated from height and weight measurements; and (3) the potential for non-linear changes over time. Because
fair/poor/very poor self-rated health (v. good/very longitudinal analysis can be biased by repeat measure-
good) (Idler & Benyamini, 1997). Psychosocial well- ment and by individual differences in susceptibility or
being was determined from interviewer ratings on likelihood of reporting PTSD symptoms, we used lon-
the RIFT of life satisfaction, relationships with friends gitudinal multilevel modeling. We modeled random
and social network involvement (Leon et al. 1999). intercepts, slopes and slopes2 to provide the best
Items were dichotomized into fair/poor/very poor life model fit. We assumed an unstructured covariance
satisfaction v. good/very good, mild/moderate/severely matrix to account for regression to the mean and en-
impaired relationships with friends v. satisfactory/non- sure that results were robust to attrition under the as-
impaired, and fair/poor social network involvement v. sumption that such attrition is not due to an
good/very good. unexpectedly high or low PCL score. We modeled
 World Trade Center DSM-IV post-traumatic stress disorder 775

the following equation: PTSD, primarily in the past (two-thirds of partial

cases). Partial PTSD was less frequent in police (6.3%)
PCLit = β0 + β1 PTSD4 + γ0i + (β2 + β3 PTSD4 + γ1i ) × t
than in non-traditional responders (9.5%) (χ2 = 7.67,
+ (β4 + β5 PTSD4 + γ2i ) × t2 + vit + εit degrees of freedom = 1, p < 0.01).
where PCL was measured among individuals (i) over
time (t), PTSD4 was the four-category ordinal variable, PTSD symptoms
vit indicated year of first monitoring visit and was Fig. 1 shows the distribution of SCID PTSD symptoms
incorporated to model change in sample make-up, for responders with active PTSD. More than two-thirds
and γki refers to random, within-person intercepts reported intrusive thoughts (B1), avoiding thoughts
and slopes. and reminders (C1–2), loss of interest and detachment
(C4–5), and four of the five hyperarousal symptoms
Ethical standards (D1–4). The least frequently reported symptoms were
All procedures contributing to this work comply with recurrent dreams and flashbacks (B2–3) and inability
the ethical standards of the relevant national and insti- to recall aspects of the trauma (C3).
tutional committees on human experimentation and The trajectories of PCL symptoms across monitoring
with the Helsinki Declaration of 1975, as revised in visits for responders with active, remitted and partial
2008. PTSD are shown in Fig. 2. The overall longitudinal
associations are provided in online Supplementary
Table S1, and fit statistics and reasoning for our
Results model choice are provided in online Supplementary
Table S2. We note that time of the first monitoring
The majority of the sample was male (91.3%),
visit was not significantly associated with initial PCL
Caucasian (78.8%) and worked in law enforcement
score (online Supplementary Table S1). The random-
(70.4%) (Table 1). The median age on 9/11 was 38
effects intercepts suggest that there were individual
years (90% range = 28–50 years). At their first monitor-
differences in PTSD symptom severity, while the sign-
ing visit, most were married (79.9%) and employed
ificant slope and slope2 covariates suggest that growth
(82.4%). Less than 10% had current depression, were
in PCL scores was heterogeneous over time. There was
active smokers or engaged in hazardous drinking.
also a negative covariance between intercepts and
Most had made at least three monitoring visits
slope and slope2, suggesting that those with higher
(73.0%) and one-third (32.9%) received some type of
scores were more likely to experience symptom reduc-
mental health treatment since 9/11.
tion over time than those with lower capability. The
Nearly one-fifth of the Stony Brook cohort (n = 571;
strong negative correlation between individual slopes
17.7%) developed WTC-PTSD. The estimated weighted
and slope2 suggests that those who experienced more
rate for the WTCHP general responder cohort was
rapid increases in PCL scores also tended to experience
18.2%. As shown in Table 1, non-traditional respon-
more deceleration, possibly indicative of floor and ceil-
ders were twice as likely to develop WTC-PTSD com-
ing effects in the sensitivity of the PCL.
pared with police (24.9% v. 14.6%). Among police,
Responders with active WTC-PTSD had the highest
the percentage with PTSD was significantly lower
PCL scores at the initial monitoring visit which
(p < 0.001) for active duty (12.0%) than retired officers
increased over time and then plateaued (Fig. 2).
(27.2%); among non-traditional responders, the percen-
Responders with remitted PTSD had lower initial
tages were similar (21.5% and 20.0%, respectively).
PCL scores that also increased over time but then
Consistent with epidemiological findings, female
decelerated. In contrast, responders with partial
gender, marital status and employment as well as
PTSD were similar initially to those with no history
smoking, hazardous drinking, current depression and
of PTSD, but their PCL scores increased in a linear
mental health treatment were significantly associated
fashion over time while those without PTSD retained
with PTSD. As expected, current depression was
their low PCL scores.
strongly co-morbid with PTSD in both police and non-
traditional responders.
Exposure and PTSD
With respect to recency, 9.7% (n = 315) of the sample
had active PTSD and 7.9% (n = 256) were in remission. One-quarter of the sample arrived on 11–12 September
Thus, slightly more than half of the responders who (25.2%), and one-quarter were in the dust cloud
developed PTSD (55.2%) had active disorder at the (23.0%). More than half were exposed to human
time of interview. This was true in both police remains (71.5%), knew someone who was injured on
(53.2%) and non-traditional responders (58.0%). 9/11 (56.0%), or suffered a loss (68.1%), primarily of
Furthermore, 5.9% (n = 191) of the sample had partial colleagues (78.1% of deaths). One-quarter (23.7%)
776 E. J. Bromet et al.

Fig. 1. Distribution of Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) post-traumatic stress
disorder (PTSD) criteria B (intrusive recollection), C (avoidance/numbing) and D (hyperarousal) symptoms among responders
with active World Trade Center PTSD in 2012–2014. Values are percentages, with 95% confidence intervals represented by
vertical bars.

Fig. 2. Predicted trajectories derived from longitudinal models of PTSD Checklist data for responders with no history of
World Trade Center (WTC) post-traumatic stress disorder (PTSD) (––), and partial (- - -), remitted (– – –) and active
WTC-PTSD (· · ·). The boxes outlined in solid gray represent 95% confidence intervals.
 World Trade Center DSM-IV post-traumatic stress disorder 777

Table 2. Relationships of exposures to WTC-PTSD compared with partial/no PTSD, and with active, remitted and partial PTSD compared
with no PTSD

WTC-PTSD Active PTSD Remitted PTSD Partial PTSD

OR (95% CI) AOR (95% CI) AOR (95% CI) AOR (95% CI)

Police responders (n = 2274)

Exposure type
Arrival 11–12 1.9 (1.3–2.6)*** 1.9 (1.2–3.0)** 2.0 (1.2–3.2)** 1.9 (1.1–3.3)*
September
In dust cloud 1.9 (1.5–2.4)*** 1.8 (1.3–2.5)*** 2.2 (1.6–3.1)*** 1.8 (1.2–2.6)*
Worked >19 days 1.5 (1.2–1.9)*** 1.6 (1.1–2.2)** 1.6 (1.1–2.2)** 1.5 (1.0–2.2)*
Human remains 3.0 (2.0–4.6)*** 3.6 (2.0–6.5)*** 2.6 (1.5–4.6)*** 1.4 (0.9–2.3)
Injury 2.1 (1.6–2.7)*** 2.1 (1.5–3.0)*** 2.2 (1.5–3.1)*** 1.5 (1.0–2.2)*
Death 2.4 (1.7–3.4)*** 2.5 (1.6–3.9)*** 2.4 (1.5–3.8)*** 1.3 (0.8–2.0)
Exposure severity (number)
High (5–6) 3.8 (2.4–6.1)*** 4.8 (2.4–9.8)*** 3.4 (1.8–6.2)*** 2.2 (1.1–4.2)*
Intermediate (3–4) 2.0 (1.2–3.1)*** 2.8 (1.4–5.6)** 1.4 (0.8–2.6) 1.5 (0.8–2.8)
No/low (0–2) 1.0 1.0 1.0 1.0
Non-traditional responders (n = 957)
Exposure type
Arrival 11–12 1.9 (1.4–2.7)*** 1.9 (1.2–2.8)** 2.5 (1.5–4.3)*** 3.3 (1.7–6.4)***
September
In dust cloud 2.0 (1.4–2.9)*** 1.8 (1.1–2.8)* 2.7 (1.7–4.4)*** 1.6 (0.9–3.1)
Worked >19 days 1.3 (0.9–2.0) 1.5 (0.9–2.5) 1.3 (0.7–2.3) 1.8 (0.9–3.3)
Human remains 2.0 (1.4–2.8)*** 1.9 (1.2–2.8)** 2.3 (1.4–3.8)*** 1.3 (0.8–2.2)
Injury 1.9 (1.3–2.5)*** 2.0 (1.4–2.9)*** 1.9 (1.2–2.9)** 1.4 (0.8–2.3)
Death 1.6 (1.2–2.1)** 1.9 (1.3–2.8)*** 1.3 (0.9–2.0) 1.5 (0.9–2.5)
Exposure severity (number)
High (5–6) 2.9 (1.8–4.5)*** 3.4 (1.9–6.2)*** 3.0 (1.6–5.5)*** 2.4 (1.2–5.1)*
Intermediate (3–4) 1.5 (1.1–2.1)* 1.9 (1.2–2.9)** 1.2 (0.7–1.9) 1.1 (0.6–2.0)
No/low (0–2) 1.0 1.0 1.0 1.0

WTC, World Trade Center; PTSD, post-traumatic stress disorder; OR, odds ratio; CI, confidence interval; AOR, adjusted
odds ratio.
* p < 0.05, ** p 4 0.01, *** p 4 0.001.

experienced five to six exposures. Police responders of arrival on 11–12 September, which increased the
were significantly more likely (p < 0.001) to report risk of partial PTSD three-fold, and being in the highest
each exposure and were twice as likely as non- exposure category, which more than doubled the risk.
traditional responders to be in the high exposure cat-
egory (28.4% v. 12.4%).
Relationships of WTC-PTSD with health and
Because responder type was significantly associated
psychosocial well-being
with both exposure and PTSD, we analysed the asso-
ciations of exposure with PTSD separately for police Table 3 shows the relationships between WTC-PTSD
and non-traditional responders. Table 2 shows that and health and psychosocial well-being. Findings
among police, each exposure increased the risk of from the unadjusted analyses indicated that WTC-
WTC-PTSD and of active, remitted and, to a lesser ex- PTSD, especially active PTSD, was significantly
tent, partial PTSD. The largest odds ratios were for ex- associated with each of the health and psychosocial
posure to human remains and experiencing five to six variables. In addition, we found a set of graded rela-
exposures. Among non-traditional responders, the tionships across active, remitted and partial PTSD for
associations of exposures with WTC-PTSD and with each variable except severe obesity. After adjusting
active and remitted PTSD were also significant, albeit for exposure severity, demographic characteristics
somewhat weaker. Associations with partial PTSD and other PTSD risk factors (smoking, hazardous
were by and large non-significant with the exceptions drinking, depression, mental health treatment),
 778
E. J. Bromet et al.
Table 3. Associations of WTC-PTSD with health and well-being: binomial and multinomial logistic regression analyses

Unadjusted analysis Adjusted analysisa

WTC-PTSD WTC-PTSD
v. partial/none Active PTSD Remitted PTSD Partial PTSD None v. partial/none Active PTSD Remitted PTSD Partial PTSD None

Variables OR (95% CI) aOR (95% CI) aOR (95% CI) aOR (95% CI) Ref AOR (95% CI) AOR (95% CI) AOR (95% CI) AOR (95% CI) Ref

Health status
Respiratory symptoms 2.7 (2.3–3.3)*** 4.6 (3.5–5.9)*** 1.6 (1.3–2.1)*** 1.4 (1.0–1.8)* 1.0 1.7 (1.3–2.2)*** 2.6 (1.8–3.8)*** 1.4 (1.0–1.9)* 1.3 (0.9–1.8) 1.0
BMI 535 kg/m2 1.3 (1.1–1.7)** 1.3 (1.0–1.7) 1.5 (1.1–2.0)** 1.2 (0.8–1.7) 1.0 1.3 (1.0–1.8) 1.1 (0.7–1.8) 1.5 (1.0–2.1)* 1.1 (0.7–1.7) 1.0
Fair/poor health 4.4 (3.6–5.3)*** 7.6 (5.8–9.9)*** 2.7 (2.1–3.5)*** 1.7 (1.3–2.4)*** 1.0 1.9 (1.5–2.5)*** 2.6 (1.7–3.7)*** 1.8 (1.3–2.4)*** 1.7 (1.2–2.4)** 1.0
Psychosocial status
Fair/poor satisfaction 10.5 (8.5–12.9)*** 28.1 (20.3–38.9)*** 4.8 (3.7–6.3)*** 1.8 (1.2–2.5)** 1.0 3.5 (2.7–4.7)*** 7.6 (4.9–11.7)*** 2.4 (1.7–3.4)*** 1.3 (0.8–2.0) 1.0
Impaired friendships 2.4 (1.9–2.9)*** 3.7 (2.9–4.8)*** 1.2 (0.8–1.6) 0.7 (0.4–1.1) 1.0 1.2 (0.9–1.6) 1.9 (1.2–2.8)** 0.7 (0.5–1.1) 0.7 (0.4–1.1) 1.0
Fair/poor social 2.5 (2.1–3.1)*** 3.7 (2.9–4.8)*** 1.7 (1.3–2.2)*** 1.4 (1.1–2.0)* 1.0 1.4 (1.2–2.0)** 2.2 (1.5–3.1)*** 1.2 (0.9–1.7) 1.4 (0.9–2.0) 1.0
support

WTC, World Trade Center; PTSD, post-traumatic stress disorder; OR, odds ratio; CI, confidence interval; aOR, odds ratio in multinomial regression; ref, reference; AOR, adjusted
odds ratio; BMI, body mass index.
a
Adjusted for variables significant in Tables 1 and 2: responder type, exposure severity, gender, employment, marital status, smoking, hazardous drinking, current depression and
mental health treatment since 11 September 2001.
* p < 0.05, ** p 4 0.01, *** p 4 0.001.
 World Trade Center DSM-IV post-traumatic stress disorder 779

WTC-PTSD was significantly associated with respira- The findings, however, require independent confi-
tory symptoms, subjective health, life satisfaction and rmation. Similar to other major disasters, such as the
social support, but not severe obesity or poorer rela- Amsterdam El Al crash (e.g. Huizink et al. 2006),
tionships with friends. The graded pattern of relation- the Oklahoma City bombing (North et al. 2002) and
ships with active, remitted and partial PTSD was the Chernobyl nuclear power plant accident (Loga-
diminished with the exception of life satisfaction, on novsky et al. 2008), there is no complete list of WTC
which responders with active PTSD were more than responders. The three largest cohorts are the
seven times as likely and those with remitted PTSD WTCHP, which verifies responder status, the
more than twice as likely than unaffected responders New York City firefighter cohort, requiring annual
to be rated as having fair/poor satisfaction. The examinations starting before 9/11, and the WTC
adjusted odds ratio for partial PTSD with life satisfac- Health Registry, where inclusion is based on self-
tion was not significant. report. Although the percentages reported here should
be regarded cautiously, our findings are consistent
with those of previous studies of WTC responders
Discussion
and research on other rescue/recovery workers. For ex-
Nearly one-fifth of the WTC responders monitored at ample, the proportion of police responders with active
the second largest WTCHP developed DSM-IV (current) PTSD (7.8%) is in line with the estimate for
WTC-PTSD after 9/11, half of whom had active dis- WTC retired firefighters 7 years after 9/11 (6.5%;
order 11–13 years on. The most frequent symptoms Chiu et al. 2011) and with the global pooled estimate
in the active PTSD group were avoidance and hyperar- of 10% reported in a recent meta-analysis of a world-
ousal symptoms, while intrusive recollection symp- wide sample of >20 000 rescue workers (Berger et al.
toms were less commonly endorsed. The longitudinal 2012). The percentage with post-9/11 PTSD in our sam-
trajectories of PTSD symptomatology rated on the ple (17.7%) and the weighted percentage for the entire
PCL showed a modestly increasing slope for respon- WTCHP (18.2%) are consistent with the lifetime rate of
ders with active PTSD and a decelerating pattern for 18.7% in the National Vietnam Veterans Readjustment
the remitted group. More than a decade after 9/11, Study (NVVRS) theater cohort assessed with the
WTC exposures remained strongly predictive of both SCID 20–25 years later (Dohrenwend et al. 2008).
active and remitted PTSD, especially among police Furthermore, the associations reported here for expos-
responders. WTC-PTSD was strongly associated with ure, demographic and other risk factors are consistent
health and psychosocial well-being. While these rela- with findings from previous trauma studies
tionships were attenuated after adjustment for expos- (McFarlane, 2010; Del Gaizo et al. 2011; Kilpatrick
ure, demographic characteristics and known risk et al. 2013). Second, like other large-scale studies (e.g.
factors for PTSD, including depression, they remained NVVRS, Schlenger et al. 2007; Project VALOR, Rosen
robust more than a decade after 9/11, particularly et al. 2012), we administered the SCID rather than the
among responders with active WTC-PTSD. ‘gold standard’ CAPS primarily because of time con-
This is the first study of a broad sample of profes- straints. Third, the study was cross-sectional and ob-
sional and non-traditional WTC responders designed servational though the inclusion of serial symptom
to examine the extent of DSM-IV WTC-related PTSD data enriched the clinical results. Fourth, like other
based on a clinician-administered diagnostic assess- WTC studies, we did not have an unexposed compari-
ment (SCID) and associations with psychosocial well- son group. Last, this report focused exclusively on
being determined from a reliable semi-structured WTC-PTSD. However, responders were also at
interview (RIFT). The interviewing team was com- increased risk of depression and other anxiety disor-
posed of master’s-level clinical psychologists who ders (Fullerton et al. 2004; Alexander & Klein, 2009)
reviewed medical records prior to each interview to en- and were exposed to prior and subsequent stressors.
hance the accuracy of the assessments. A key emphasis A recent study found an interaction effect of WTC ex-
of the training was distinguishing between symptoms posure and post-9/11 stressful life events on PTSD
directly related to 9/11 exposures and ones that were symptomatology (Zvolensky et al. 2015). Future studies
secondary to 9/11 physical illnesses, particularly re- of DSM-IV PTSD in WTC responders will directly ad-
spiratory and gastrointestinal conditions. An addition- dress these co-morbidities and sources of stress.
al strength was the inclusion of a comprehensive set of Within the context of these limitations, the current
potential confounders, including hazardous drinking, study sheds light on three issues. First, more than a
smoking, current DSM-IV depression and mental decade after 9/11, the catastrophic exposures continued
health service use, in analysing associations of active, to have an adverse impact on clinically defined PTSD
remitted and partial PTSD with health and psycho- in both professional and non-traditional WTC respon-
social well-being. ders. Although every disaster is unique, the findings
780 E. J. Bromet et al.

add to the few long-term follow-ups of traumatic treatment planning. In fact, the Stony Brook clinic is
events, including Chernobyl clean-up workers modeled on an integrated physical and mental health
(Loganovsky et al. 2008), Vietnam veterans (Schlenger care system, offering on-site mental and physical
et al. 2007) and Israeli combat veterans (Solomon health care (Luft et al. 2012).
et al. 2009). The percentage of police with active In conclusion, the long-term impact of 9/11 expo-
PTSD (7.8%) was lower than that of non-traditional sures, like combat experiences in military cohorts, is
responders (14.4%) and also lower than the rate of reflected in the substantial percentage with PTSD
probable PTSD in police in the WTC Health Registry more than a decade after 9/11 and its strong associa-
assessed with the PCL (11.0% in 2011–2012; Cone tions with physical health and psychosocial well-being,
et al. 2015). It has been argued that active-duty police especially reduced satisfaction with life. Responders
minimize their symptoms because of employment- experienced multiple exposures simultaneously and,
related concerns (Luft et al. 2012), and, indeed, a like other rescue/recovery workers, were at increased
lower percentage of active-duty police had WTC- risk by virtue of the combination of proximity to the
PTSD compared with retired police officers. Even disaster site, duration of work and intensity of the
with this potential bias, the persistence of PTSD is exposures (Benedek et al. 2007). The concurrent asso-
striking, with approximately 50% of affected respon- ciations with poorer health and psychosocial well-
ders having active PTSD. Interestingly, the percentage being were striking, particularly for responders with
with remitted PTSD 12–14 years post-9/11 was com- active PTSD though the remitted group also had a
parable with the median time to remission (14 years) 2-fold increased level of dissatisfaction with life and
for participants with PTSD in the 2007 Australian negative subjective health. These results suggest the
National Survey of Mental Health and Wellbeing need for monitoring programs to consider all
(Chapman et al. 2012). aspects of health as defined by the World Health
Second, although the diagnosis of PTSD connotes Organization, namely, mental, physical and social
‘flashbacks’ and ‘nightmares’ in popular culture, well-being. Future longitudinal studies are needed to
these symptoms were far less frequently reported determine the continued persistence of PTSD in this co-
than avoidance and hyperarousal symptoms. hort, the potential for relapse among remitted cases
Furthermore, the trajectory of PTSD symptoms and for delayed onset in the unaffected group, and
among responders with active PTSD showed progres- the extent to which the course of PTSD predicts decre-
sively increasing symptom severity, indicating both ments in health and psychosocial well-being during
unmet need for treatment and potential undertreat- the second decade after 9/11.
ment for those receiving mental health services.
Although ‘gold standard’ treatments, such as cogni-
Supplementary material
tive–behavioral therapy and prolonged exposure ther-
apy, were designed to address PTSD symptoms, a To view supplementary material for this article, please
recent meta-analysis (Watts et al. 2013) showed that visit http://dx.doi.org/10.1017/S0033291715002184
these treatments potentially benefit only one in two
patients. Even so, given that 50% of responders with
Acknowledgements
PTSD had active disorder, there is a clear need to
continue to monitor the cohort and to encourage the This research was supported by Centers for Disease
group with active PTSD to seek evidence-based Control and Prevention/National Institute for
treatment. Occupational Safety and Health (CDC/NIOSH) grant
Third, PTSD was significantly associated with sev- 200-2011-39410 to E.J.B., R.K. and B.J.L.
eral aspects of health and psychosocial well-being, es- We gratefully acknowledge the support of the WTC
pecially self-reported fair/poor health and reduced responders for generously contributing their time and
life satisfaction. Even after adjustment for exposure se- energy to this project. We also thank the following
verity and other risk factors, the reach of PTSD into staff of the Stony Brook WTCHP for facilitating the
other domains of life was clearly shown and was study: Peter Arce, Julie Broihier, Katherine Guerrera,
strongest for the group with active PTSD. The current Janet Lavelle, Nicole Lee, Brittain Mahaffey, Lindsay
associations with the health variables, especially re- Pratt, and Nwakaego (Ada) Ukonu, Oren Shapira,
spiratory symptoms and negative subjective evalua- Ph.D., Chris Ray and the WTCHP Data Monitoring
tions obtained as part of the monitoring visit, are Center which provided invaluable assistance with se-
consistent with the recent national initiative to provide curing data. The findings and conclusions in this article
integrated physical and mental health care (Huffman are those of the authors and do not represent the
et al. 2014). The findings also suggest that a biopsycho- official position of NIOSH, the CDC or the US Public
social formulation should be an integral part of Health Service.
 World Trade Center DSM-IV post-traumatic stress disorder 781

Declaration of Interest PTSD among disaster workers deployed to the World Trade
Center following the attacks of September 11th. Journal of
None. Traumatic Stress 24, 506–514.
Dasaro CR, Holden WL, Berman KD, Crane MA, Kaplan JR,
Lucchini RG, Luft BJ, Moline JM, Teitelbaum SL,
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