Trauma- and stressor-related disorders involve exposure to a stressful or traumatic event.6 These were previously grouped with anxiety disorders but are now considered a distinct category of disorders.

Disorders included in this category include:

• Acute stress disorder, which is characterized by the emergence of severe anxiety for up to a one month period after exposure to a traumatic event such as natural disasters, war, accidents, and witnessing a death.
  As a result, the individual may experience dissociative symptoms such as a sense of altered reality, an inability to remember important aspects of the event, and vivid flashbacks as if the event were reoccurring. Other symptoms can include reduced emotional responsiveness, distressing memories of the trauma, and difficulty experiencing positive emotions.
• Adjustment disorders can occur as a response to a sudden change such as divorce, job loss, end of a close relationship, a move, or some other loss or disappointment. This type of psychological disorder can affect both children and adults and is characterized by symptoms such as anxiety, irritability, depressed mood, worry, anger, hopelessness, and feelings of isolation.  
• Post-traumatic stress disorder can develop after an individual has experienced exposure to actual or threatened death, serious injury, or sexual violence. Symptoms of PTSD include episodes of reliving or re-experiencing the event, avoiding things that remind the individual about the event, feeling on edge, and having negative thoughts. Nightmares, flashbacks, bursts of anger, difficulty concentrating, exaggerated startle response, and difficulty remembering aspects of the event are just a few possible symptoms that people with PTSD might experience.
• Reactive attachment disorder can result when children do not form normal healthy relationships and attachments with adult caregivers during the first few years of childhood. Symptoms of the disorder include being withdrawn from adult caregivers and social and emotional disturbances that result from patterns of insufficient care and neglect.