PSYX 340 Psychological Disorders · Unit 1: Foundations, anxiety and trauma · on Exam 1
1.5 Disorders of trauma and stress
Study notes for Disorders of trauma and stress in PSYX 340 Psychological Disorders at Montana State University: the big ideas, a worked example, common mistakes and an exam tip. The same topic has endless practice questions and flashcards in Mathub.
Big ideas
- The stress response uses two systems: the autonomic nervous system (sympathetic arousal, the fight-or-flight response) and the HPA axis (hypothalamus → pituitary → adrenal glands, releasing cortisol).
- Acute stress disorder and PTSD both follow exposure to actual or threatened death, serious injury or sexual violence (experienced, witnessed, learned about in a close person, or repeated exposure to details at work). Acute stress disorder lasts 3 days to 1 month; PTSD lasts more than a month and can have delayed expression (full criteria met 6 months or more later).
- PTSD symptoms fall in four groups: intrusion (memories, nightmares, flashbacks), avoidance of reminders, negative changes in thinking and mood (blame, detachment, inability to feel positive emotions) and arousal and reactivity (hypervigilance, startle, sleep problems, irritability).
- Risk factors include biological differences (cortisol, a smaller hippocampus), personality, childhood adversity, weak social support and how severe the trauma was. Most people exposed to trauma do not develop PTSD.
- Treatments with good evidence include trauma-focused CBT (prolonged exposure, cognitive processing therapy) and EMDR; antidepressants help some people. Psychological debriefing right after a disaster has not been shown to prevent PTSD and may even hurt. Adjustment disorder covers emotional or behavioral symptoms that begin within 3 months of an ordinary stressor.
Worked example
Ten days after a car crash, Maria has nightmares, avoids driving, feels numb and jumps at loud noises. What is the diagnosis now, and what would change if the symptoms were still there two months later?
Show the solution
At 10 days, with symptoms lasting between 3 days and a month, the diagnosis is acute stress disorder. If the same symptoms persisted beyond one month, the diagnosis would become PTSD. Duration since the trauma is what separates the two.
Common mistakes
- Diagnosing PTSD in the first month after a trauma. That window belongs to acute stress disorder.
- Treating any stressful event as qualifying trauma. PTSD requires exposure to death, serious injury or sexual violence; a breakup leads to adjustment disorder, if anything.
- Assuming debriefing prevents PTSD. The evidence says it does not.
Exam tipRemember the timeline: under 3 days is a normal reaction, 3 days to 1 month is acute stress disorder, over 1 month is PTSD, and over 6 months before full criteria is “with delayed expression”.
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