Alterations in awareness can include depersonalization, a detached sense of oneself (e.g., seeing oneself from the other side of the room), or derealization, having a distorted view of one’s surroundings (e.g., perceiving that things are moving in slow motion, seeing things in a daze, not being aware of events that one would normally encode). Some individuals also report an inability to remember an important aspect of the traumatic event that was presumably encoded. This symptom is attributable to dissociative amnesia and is not at- tributable to head injury, alcohol, or drugs.
Stimuli associated with the trauma are persistently avoided. The individual may refuse to discuss the traumatic experience or may engage in avoidance strategies to minimize awareness of emotional reactions (e.g., excessive alcohol use when reminded of the ex- perience). This behavioral avoidance may include avoiding watching news coverage of the traumatic experience, refusing to return to a workplace where the trauma occurred, or avoiding interacting with others who shared the same traumatic experience.
It is very common for individuals with acute stress disorder to experience problems with sleep onset and maintenance, which may be associated with nightmares or with gen- eralized elevated arousal that prevents adequate sleep. Individuals with acute stress dis- behavior with little provocation. Acute stress disorder is often characterized by a height- ened sensitivity to potential threats, including those that are related to the traumatic ex- perience (e.g., a motor vehicle accident victim may be especially sensitive to the threat potentially caused by any cars or trucks) or those not related to the traumatic event (e.g., fear of having a heart attack). Concentration difficulties, including difficulty remembering daily events (e.g., forgetting one’s telephone number) or attending to focused tasks (e.g., following a conversation for a sustained period of time), are commonly reported. Individ- uals with acute stress disorder may be very reactive to unexpected stimuli, displaying a heightened startle response or jumpiness to loud noises or unexpected movements (e.g., the individual may jump markedly in the response to a telephone ringing).
Individuals with acute stress disorder commonly engage in catastrophic or extremely neg- ative thoughts about their role in the traumatic event, their response to the traumatic ex- perience, or the likelihood of future harm. For example, an individual with acute stress disorder may feel excessively guilty about not having prevented the traumatic event or about not adapting to the experience more successfully. Individuals with acute stress dis- order may also interpret their symptoms in a catastrophic manner, such that ﬂashback memories or emotional numbing may be interpreted as a sign of diminished mental ca- pacity. It is common for individuals with acute stress disorder to experience panic attacks in the initial month after trauma exposure that may be triggered by trauma reminders or may apparently occur spontaneously. Additionally, individuals with acute stress disorder may display chaotic or impulsive behavior. For example, individuals may drive reck- lessly, make irrational decisions, or gamble excessively. In children, there may be sig- nificant separation anxiety, possibly manifested by excessive needs for attention from caregivers. In the case of bereavement following a death that occurred in traumatic cir- cumstances, the symptoms of acute stress disorder can involve acute grief reactions. In such cases, reexperiencing, dissociative, and arousal symptoms may involve reactions to the loss, such as intrusive memories of the circumstances of the individual’s death, disbe- lief that the individual has died, and anger about the death. Postconcussive symptoms (e.g., headaches, dizziness, sensitivity to light or sound, irritability, concentration deficits), which occur frequently following mild traumatic brain injury, are also frequently seen in individuals with acute stress disorder. Postconcussive symptoms are equally common in brain-injured and non—brain-injured populations, and the frequent occurrence of postcon- cussive symptoms could be attributable to acute stress disorder symptoms.