Anxiety, Obsessive-Compulsive and Trauma-Related Disorders
This domain tests separation of the anxiety disorders, recognition of OCD whatever its content, and correct trauma-related diagnosis including the ICD-11 distinction between PTSD and complex PTSD.
Core diagnostic rules
- Panic disorder: recurrent unexpected panic attacks plus at least one month of anticipatory anxiety or avoidance. Agoraphobia is coded separately and can occur without panic.
- Generalised anxiety disorder: excessive, difficult-to-control worry across several domains for at least six months, with three of six symptoms (restlessness, fatigability, poor concentration, irritability, muscle tension, sleep disturbance).
- Social anxiety disorder: fear of negative evaluation in social or performance situations, with avoidance.
- OCD: obsessions (intrusive, unwanted, ego-dystonic) and compulsions (repetitive acts to neutralise distress), time-consuming or causing impairment. Insight is specified as good, fair, poor, or absent/delusional.
- PTSD: exposure to trauma followed by intrusion, avoidance, negative alterations in cognition and mood, and hyperarousal, lasting more than one month. ICD-11 complex PTSD adds affective dysregulation, negative self-concept and disturbed relationships.
- Acute stress reaction: symptoms within days and resolving within one month.
Treatment rules
First-line pharmacotherapy for anxiety disorders and OCD is an SSRI (or venlafaxine, or pregabalin in generalised anxiety). OCD typically needs higher doses and 8-12 weeks before judging response. Trauma-focused CBT and EMDR are first-line for PTSD. Benzodiazepines are for short-term crisis use only, because of dependence, and are avoided in PTSD. Single-session psychological debriefing is not recommended.
Worked example
A 31-year-old fears contaminating his child. He knows the fear is excessive but washes repeatedly and counts to six. Reasoning: ego-dystonic intrusive thoughts plus neutralising rituals with preserved insight equal OCD, not generalised anxiety. The distinguishing feature is the functional link between a specific intrusive thought and a specific ritual, whereas worry in GAD is about real-life concerns and is not neutralised in this way.
Traps that cost marks
Missing OCD when insight is poor and calling it psychosis. Diagnosing PTSD within the first month. Prescribing long-term benzodiazepines. Using relaxation alone for OCD instead of ERP. Forgetting medical mimics such as thyrotoxicosis, arrhythmia, phaeochromocytoma and caffeine or stimulant use.