Anxiety, Obsessive-Compulsive, Trauma- and Stressor-Related, and Dissociative Disorders
What the exam tests
This domain tests duration criteria, fear versus anxiety, insight, trauma timing and dissociation. Questions often ask you to distinguish normal stress reactions from disorder and to choose exposure-based treatment.
Core rules
- Panic attacks peak within minutes; panic disorder includes recurrent unexpected attacks plus worry or behaviour change. Agoraphobia is fear of escape being difficult.
- Generalised anxiety disorder requires excessive worry for six months with several somatic or cognitive symptoms.
- OCD requires obsessions and/or compulsions that are time-consuming or cause impairment; insight ranges from good to absent.
- Acute stress disorder occurs from three days to one month after trauma; PTSD requires symptoms for more than one month with intrusion, avoidance, negative cognition or mood, and hyperarousal.
- Dissociation includes depersonalisation, derealisation and dissociative amnesia; it can mimic psychosis but is not a delusion.
Worked example
Two months after an assault, a woman has intrusive images, nightmares, avoidance of buses, hypervigilance and negative beliefs about safety. This is PTSD, not acute stress disorder, because symptoms persist beyond one month. The reasoning is the trauma exposure plus four symptom clusters and functional impairment. Trauma-focused CBT or EMDR is first-line; medication is an option, not a substitute for trauma-focused work.
Traps that cost marks
Do not diagnose PTSD within the first month; use acute stress disorder. Do not mistake obsessive doubts for delusions when insight is retained. Do not miss medical mimics of panic such as arrhythmia, thyrotoxicosis or pheochromocytoma. Do not label dissociation as schizophrenia without psychotic criteria.