314 CHAPTER 7
What Is Posttraumatic Stress Disorder?
Posttraumatic stress disorder (PTSD) is diagnosed when people who have experi-
enced a trauma persistently reexperience the traumatic event, avoid stimuli related
to the event, and have symptoms of anxiety and hyperarousal; these symptoms must
persist for at least a month (American Psychiatric Association, 2000). These three
symptoms form the posttrauma criteria for PTSD, as shown in Table 7.17 (Criteria
B, C, and D), and they may not emerge until months or years after the traumatic
event. Table 7.18 presents other information about PTSD. Case 7.7 describes the
experiences of a man with PTSD.Posttraumatic stress disorder (PTSD)
The anxiety disorder that arises a month or
more after a traumatic event and that involves
a persistent reexperiencing of the event,
avoiding stimuli related to the event, and
symptoms of anxiety and hyperarousal that
persist for at least a month.
Acute stress disorder
The anxiety disorder that arises within a
month after a traumatic event and that
involves reexperiencing of the event, avoiding
stimuli related to the event, and symptoms of
anxiety, hyperarousal, and dissociation that
last for less than a month.
CASE 7.7 • FROM THE OUTSIDE: Posttraumatic Stress Disorder
A. C. was a 42 year old single man, a recent immigrant who, one year before his appearance
at the clinic, had walked into his place of work while an armed robbery was taking place. Two
men armed with guns hit him over the head, threatened to kill him, tied him up and locked
him in a closet with four other employees. He was released from the closet 4 hours later when
another employee came in to work. The police were notifi ed and A. C. was taken to the hospital
where his head wound was sutured and he was released. For two weeks after the robbery A. C.
continued to function as he had before the robbery with no increase in anxiety.
One day while waiting to meet someone on the street he was struck by the thought that he
might meet his assailants again. He began to shiver, felt his heart race, felt dizzy, started to
sweat and felt that he might pass out. He was brought to an emergency room, examined and
released with a referral to victims’ services. His anxiety increased so much that he was unable
to return to work because it reminded him of the robbery. He started to have sleep diffi culties,
waking in the middle of the night to check the front door lock at home. He quit his job and
dropped out of school due to his anxiety. He would have fl ashbacks of the guns that were used
in the robbery and started to avoid people on the street who reminded him of the robbers. He
began to feel guilty that he had entered the offi ce while the robbery was in progress feeling
that he somehow should have known what was occurring. His avoidance extended to the sub-
way, exercising and socializing with friends.
(New York Psychiatric Institute, 2006)A. C.’s symptoms didn’t arise until 2 weeks after the robbery. If his symptoms
had lasted for less than 4 weeks or if he had sought help from a mental health cli-
nician within a month of the event, A. C. might have been diagnosed with acute
stress disorder. Like PTSD, acute stress disorder also involves reexperiencing the
traumatic event, avoiding stimuli related to the event, and exhibiting symptoms of
anxiety and hyperarousal. However, unlike PTSD, the DSM-IV-TR criteria for acute
stress disorder also involves symptoms of dissociation (American Psychiatric Asso-
ciation, 2000), namely:- feeling emotionally detached or numb;
- feeling less aware of the environment, which some people describe as “being in a
daze”; - derealization, in which the perception or experience of the external world seems
strange or unreal, as though seen through a pane of glass; - depersonalization, in which the perception or experience of oneself (either one’s
body or one’s mental processes) is altered to the point of feeling like an observer,
seeing oneself from the outside; and - dissociative amnesia, or loss of memory of important elements of the traumatic event.
Moreover, the symptoms must occur within 4 weeks of the trauma (as A. C.’s
did), last no more than 4 weeks, and must cause distress or impair functioning. Ap-
proximately 80% of those with acute stress disorder have symptoms that persist for
more than a month, at which point the diagnosis then changes to PTSD (Harvey &
Bryant, 2002). Unlike A. C., though, most people who experience trauma do not
develop PTSD (Breslau et al., 1998; Resnick et al., 1993; Shalev et al., 1998).