Posttraumatic Stress Disorder Study Pack

Kibin's free study pack on Posttraumatic Stress Disorder includes a 3-section study guide, 8 quiz questions, 10 flashcards, and 1 open-ended Explain review question. Sign up free to track your progress toward mastery, plus upload your own notes and recordings to create personalized study packs organized by course.

Last updated May 21, 2026

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Posttraumatic Stress Disorder Study Guide

Unpack the biology and psychology behind PTSD, from DSM-5 symptom clusters — intrusion, avoidance, mood changes, and hyperarousal — to the neurological mechanisms driving them, including amygdala reactivity and HPA axis dysregulation. This pack also covers risk factors, the distinction between PTSD and Acute Stress Disorder, and leading treatments like Prolonged Exposure, CPT, EMDR, and SSRIs.

Key Takeaways

  • •Posttraumatic stress disorder (PTSD) develops after exposure to actual or threatened death, serious injury, or sexual violence, and is distinguished from normal stress reactions by its persistence beyond one month and its significant functional impairment.
  • •The DSM-5 organizes PTSD symptoms into four clusters: intrusion (e.g., flashbacks, nightmares), avoidance of trauma-related stimuli, negative alterations in cognition and mood, and marked alterations in arousal and reactivity.
  • •Biological vulnerability factors include heightened amygdala reactivity, reduced hippocampal volume, and dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, which together sustain a chronic threat-response state.
  • •Not everyone exposed to trauma develops PTSD; risk is shaped by the severity and duration of the trauma, prior trauma history, lack of social support, and individual differences in stress reactivity.
  • •Cognitive-behavioral therapies — particularly Prolonged Exposure and Cognitive Processing Therapy — and EMDR are the best-supported treatments, while SSRIs such as sertraline and paroxetine are the primary pharmacological options.
  • •PTSD is distinct from Acute Stress Disorder, which involves similar symptoms but resolves within one month of the traumatic event; PTSD requires symptoms lasting longer than one month.
  • •The physiological stress response, mediated by the sympathetic-adrenal-medullary axis and the HPA axis, underlies the hyperarousal symptoms of PTSD and explains why trauma can produce lasting changes in hormone levels and nervous system functioning.

Defining PTSD: Diagnostic Criteria and Core Features

Posttraumatic stress disorder is a trauma- and stressor-related disorder that emerges when exposure to an overwhelming event produces a persistent, maladaptive psychological and physiological response lasting more than one month and causing significant disruption to daily functioning.

Qualifying Traumatic Events

  • •Direct personal experience of actual or threatened death, serious injury, or sexual violence qualifies as a traumatic stressor.
  • •Witnessing such events happening to others, learning that a close family member or friend experienced them, or repeated first-hand exposure to traumatic details (e.g., first responders repeatedly processing abuse cases) also qualifies.
  • •PTSD is not diagnosed when the stressor is simply a stressful life event such as divorce or job loss — the event must involve extreme threat.

Distinguishing PTSD from Normal Stress Responses

  • •A normal acute stress response involves temporary anxiety, sleep disturbance, and hypervigilance immediately after danger — this is adaptive.
  • •PTSD is diagnosed only when symptoms persist beyond one month post-trauma and cause clinically significant distress or functional impairment in social, occupational, or other areas.
  • •Acute Stress Disorder covers the same symptom clusters but applies specifically to the window of three days to one month following the traumatic event; if symptoms continue past one month, the diagnosis shifts to PTSD.

Specifiers Recognized by the DSM-5

  • •A 'with dissociative symptoms' specifier applies when the individual experiences persistent depersonalization (feeling detached from one's own mental processes or body) or derealization (sense that surroundings are unreal).
  • •A 'with delayed expression' specifier applies when full diagnostic criteria are not met until at least six months after the event.

The Four DSM-5 Symptom Clusters

The DSM-5 organizes PTSD's wide-ranging symptoms into four distinct clusters, each reflecting a different dimension of how trauma disrupts cognition, emotion, behavior, and physiological regulation.

Intrusion Symptoms

  • •Involuntary, distressing memories of the traumatic event intrude into conscious awareness despite efforts to suppress them.
  • •Flashbacks are dissociative episodes in which the individual re-experiences the trauma as if it were happening in the present, ranging from brief mental images to complete loss of awareness of current surroundings.
  • •Recurrent trauma-related nightmares and intense psychological or physiological distress when exposed to internal or external cues that symbolize the trauma are also classified here.

Avoidance Symptoms

  • •Persistent effortful avoidance of distressing trauma-related thoughts, feelings, memories, or external reminders such as people, places, conversations, activities, and objects.
  • •Avoidance is functionally significant because it prevents emotional processing of the trauma and often leads to progressive social and occupational withdrawal.

Negative Alterations in Cognition and Mood

  • •Persistent negative beliefs about oneself or the world (e.g., 'I am permanently damaged'; 'Nowhere is safe'), distorted blame of self or others for causing the trauma, and persistent shame or guilt fall into this cluster.
  • •Diminished interest in meaningful activities, feelings of detachment or estrangement from others, and persistent inability to experience positive emotions (emotional numbing) are also included.
  • •Some individuals experience trauma-induced amnesia — an inability to remember key aspects of the traumatic event that is not due to head injury or substances.

Alterations in Arousal and Reactivity

  • •This cluster captures the chronic activation of the threat-response system: hypervigilance, exaggerated startle response, irritability or aggressive outbursts, reckless or self-destructive behavior, and sleep disturbances.
  • •Unlike the fear response that occurs only in the presence of a threat, the hyperarousal in PTSD is persistent and often occurs in the absence of any real danger.

About this Study Pack

Created by Kibin to help students review key concepts, prepare for exams, and study more effectively. This Study Pack was checked for accuracy and curriculum alignment using authoritative educational sources. See sources below.

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