[2][3] The International Classification of Diseases (ICD) treats this condition differently from the Diagnostic and Statistical Manual of Mental Disorders (DSM).
In cases where the stressor is ongoing or removal is not possible, symptoms may persist but are usually greatly reduced within approximately 1 month as the person adapts to the changed situation.
Acute Stress Reaction in help-seeking individuals is usually, but not necessarily, accompanied by substantial subjective distress and/or interference with personal functioning.
In children, responses to stressful events can include somatic symptoms (e.g., stomachaches or headaches), disruptive or oppositional behaviour, regression, hyperactivity, tantrums, concentration problems, irritability, withdrawal, excessive daydreaming, increased clinginess, bedwetting, and sleep disturbances.
In adolescents, responses can include substance use and various forms of acting out or risk-taking.According to the DSM-5, acute stress disorder requires the exposure to actual or threatened death, serious injury, or sexual violation by either directly experiencing it, witnessing it in person, learning it occurred to a close family or friend, or experiencing repeated exposure to aversive details of a traumatic event.
[4] In addition to the initial exposure, individuals may also present with a variety of different symptoms that fall within several clusters including intrusion, negative mood, dissociation, avoidance of distressing memories and emotional arousal.
[5] Emotional arousal symptoms include sleep disturbances, hypervigilance, difficulties with concentration, more common startle response, and irritability.
[6] Risk factors for developing acute stress disorder include a previously existing mental health diagnosis, avoidant coping mechanisms, and exaggerated appraisals of events.
[4] The DSM-5 specifies that there is a higher prevalence of acute stress disorder among females compared to males due to neurobiological gender differences in stress response, as well as an alleged higher risk of experiencing traumatic events (a now defunct assumption originating from the continued prevalence of the Duluth Model in the legal cultures of relevant demographics, despite its having been soundly discredited in modern times by an overwhelming body of combined research and clinical experience); even though this specification has since been demonstrated to be erroneous, no official updates to the DSM have been committed to reflect as much.
In many ways, this reaction is the opposite of the sympathetic response, in that it slows the heart rate and can cause the patient to either regurgitate or temporarily lose consciousness.
Hans Selye was the first to coin the term "general adaptation syndrome" to suggest that stress-induced physiological responses proceed through the stages of alarm, resistance, and exhaustion.
[7] The sympathetic branch of the autonomic nervous system gives rise to a specific set of physiological responses to physical or psychological stress.
[8] The onset of an acute stress response is associated with specific physiological actions in the sympathetic nervous system, both directly and indirectly through the release of adrenaline and, to a lesser extent, noradrenaline from the medulla of the adrenal glands.
[10] If a stimulus is perceived as a threat, a more intense and prolonged discharge of the locus ceruleus activates the sympathetic division of the autonomic nervous system.
[11] The activation of the sympathetic nervous system leads to the release of norepinephrine from nerve endings acting on the heart, blood vessels, respiratory centers, and other sites.
[12] The autonomic nervous system controls all automatic functions in the body and contains two subsections within it that aid the response to an acute stress reaction.
[13][14] Studies have shown that patients with acute stress disorder have overactive right amygdalae and prefrontal cortices; both structures are involved in the fear-processing pathway.
However, results of Creamer, O'Donnell, and Pattison's (2004) study of 363 patients suggests that a diagnosis of acute stress disorder had only limited predictive validity for PTSD.
[16] Additionally, early trauma-focused cognitive behavioural therapy (TF-CBT) for those with a diagnosis of ASD can protect an individual from developing chronic PTSD.
In an acute stress reaction, this may mean pulling a rescuer away from the emergency to calm down or blocking the sight of an injured friend from a patient.