Posttraumatic Stress Disorder 275
sonal assault, suicide, serious accident, and se rious injury. The disorder may be especially
severe or long-lasting when the stressor is interpersonal and intentiona l (e.g., torture, sex-
ual violence). 
The traumatic event can be reexperienced in various ways. Commonly, the individual
has recurrent, involuntary, and intrusive recollect ions of the event (Criterion B1). Intrusive
recollections in PTSD are distinguished from depressive rumination in that they apply
only to involuntary and intrusive distressing memories. The emphasis is on recurrent
memories of the event that us ually include sensory, emotiona l, or physiological behavioral
components. A common reexperiencing symptom is distressing dreams that replay the
event itself or that are representative or th ematically related to th e major threats involved
in the traumatic event (Criterion B2). The in dividual may experience dissociative states
that last from a few seconds to several hours or even days , during which components of
the event are relived and the individual behaves as if the event were occurring at that mo-
ment (Criterion B3). Such events occur on a continuum from brief vi sual or other sensory
intrusions about part of the traumatic event wi thout loss of reality or ientation, to complete
loss of awareness of present surroundings. These episodes, often re ferred to as “flash-
backs,” are typically brief but can be associ ated with prolonged distress and heightened
arousal. For young children, reenactment of events related to trauma may appear in play
or in dissociative states. Intense psychological distress (Criterion B4) or physiological re-
activity (Criterion B5) often occurs when the individual is exposed to triggering events that