Panic Disorder 209
C. The disturbance is not attributable to the physiological effects of a substance (e.g., a
drug of abuse, a medication) or another medi cal condition (e.g., hyperthyroidism, car-
diopulmonary disorders).
D. The disturbance is not better explained by another mental disorder (e.g., the panic at-
tacks do not occur only in response to feared social situations, as in social anxiety dis-
order; in response to circumscribed phobic objec ts or situations, as in specific phobia;
in response to obsessions, as in obsessive-compulsive disorder; in response to re-
minders of traumatic events, as in posttraumatic stress disorder; or in response to sep-
aration from attachment figures, as in separation anxiety disorder). 
Diagnostic Features
Panic disorder  refers to recurrent unexpected panic attacks (Criterion A). A panic attack is
an abrupt surge of intense fear or intense di scomfort that reaches a peak within minutes,
and during which time four or more of a lis t of 13 physical and cognitive symptoms occur.
The term recurrent  literally means more than one un expected panic attack. The term unex-
pected  refers to a panic attack for which there is no obvious cue or trigger at the time of oc-
currence—that is, the attack appears to occu r from out of the blue, such as when the
individual is relaxing or emerging from sleep (nocturnal panic attack). In contrast, expected
panic attacks are attacks for which there is an ob vious cue or trigger, such as a situation in
which panic attacks typically occur. The determination of whether panic attacks are ex-
pected or unexpected is made by the clinicia n, who makes this judgment based on a com-
bination of careful questioning as to the sequence of events preceding or leading up to the