Anxiety, Obsessive-Compulsive and Trauma-Related Disorders
Anxiety disorders
Distinguish panic disorder (recurrent unexpected attacks plus anticipatory anxiety), agoraphobia, social anxiety disorder, generalised anxiety disorder (≥6 months of excessive worry), separation anxiety and selective mutism. Differentiate physiological anxiety from medical mimics (thyroid disease, arrhythmia, phaeochromocytoma, substance effects).
OCD and related disorders
OCD requires obsessions and/or compulsions that are time-consuming or cause distress/impairment, with insight specifiers. Related disorders include body dysmorphic disorder, hoarding disorder, trichotillomania and excoriation disorder. Traps: mislabelling OCD as psychotic (patients usually have insight); confusing OCD with generalised anxiety; missing that reassurance-seeking is a compulsion.
Trauma-related disorders
PTSD requires exposure to trauma plus intrusion, avoidance, negative cognitions/mood, and hyperarousal lasting over one month; acute stress disorder covers the first month. Complex PTSD adds affect dysregulation, negative self-concept and relational disturbance. Dissociative disorders and adjustment disorder complete the differential.
Treatment principles
First-line: CBT (including exposure and response prevention for OCD), SSRIs. Trauma-focused CBT and EMDR are first-line for PTSD; avoid routine benzodiazepines.
Worked rule of thumb
If a patient's fear is of their own thoughts rather than of external danger, think OCD; if fear follows a defined trauma with re-experiencing, think PTSD.