Posttraumatic Stress Disorder and the Concept of Complex Trauma

1. Overview & Epidemiology

PTSD sits in the ICD-10 block F43 — Reaction to severe stress, and adjustment disorders (the Debrecen lectures teach the F40–F48 "neurotic, stress-related and somatoform" group). The whole F43 family is defined by a causal external stressor — diagnosis is impossible without an identifiable trauma or life event, which separates it from the rest of psychiatry.

The F43 spectrum (by timeframe and stressor magnitude):

• Acute stress reaction (F43.0): transient, develops within minutes of an exceptional stressor, resolves within hours–days.
• Acute stress disorder (DSM-5-TR): 3 days–1 month post-trauma.
• *Posttraumatic stress disorder (F43.1):