nity study was 1.8% (1.0% fo r males; 2.6% for females). 
Development and Course
Onset of generalized amnesia is usually sudden . Less is known about the onset of localized
and selective amnesias because these amnesias ar e seldom evident, even to the individual.
Although overwhelming or intolerable events typically precede localized amnesia, its on-
set may be delayed for ho urs, days, or longer. 
Individuals may report multiple episodes of dissociative amnesia. A single episode
may predispose to future episodes. In between episodes of amnesia, the individual may or
may not appear to be acutely symptomatic. Th e duration of the forgotten events can range
from minutes to decades. Some episodes of  dissociative amnesia resolve rapidly (e.g.,
when the person is removed from combat or some other stressful situation), whereas other
episodes persist for long periods of time. So me individuals may grad ually recall the dis-
sociated memories years later. Dissociative capacities may decline with age, but not al-
ways. As the amnesia remits, there may be considerable distress, su icidal behavior, and
symptoms of posttraumatic stress disorder (PTSD). 
Dissociative amnesia has been observed in young children, adolescents, and adults.
Children may be the most difficult to evaluate because they often have difficulty under-
standing questions about amnesia, and interviewers may find it difficult to formulate child-
friendly questions about memory and amnesia. Observations of apparent dissociative am-
nesia are often difficult to differentiate from inattention, absorption , anxiety, oppositional
behavior, and learning disorders. Reports fr om several different sources (e.g., teacher,
therapist, case worker) may be needed  to diagnose amnesia in children.