Chapter 17: Post-Traumatic Stress Disorder

The historical evolution of PTSD conceptualization is traced from early military-related terminology including shell shock and war neurosis through its formal recognition in DSM-III and subsequent refinement in DSM-5, which fundamentally reconceptualized the disorder by removing it from the anxiety disorders category and establishing four primary symptom clusters reflecting the multifaceted nature of traumatic responses. The chapter details core diagnostic features encompassing involuntary trauma memories and flashbacks, psychological reactivity to trauma cues, active avoidance of reminders and internal experiences, emotional blunting and detachment, and marked hypervigilance alongside functional deterioration. Epidemiologic patterns reveal elevated lifetime prevalence rates particularly among female populations and individuals with histories of interpersonal violence, with substantial co-occurrence of major depressive disorder, substance use disorders, and additional psychiatric conditions that complicate clinical presentation and treatment planning. The biological architecture underlying PTSD is examined through fear conditioning mechanisms and amygdala-centered threat detection, hippocampal dysfunction affecting contextual memory processing, reduced prefrontal regulatory capacity, and dysregulation of the hypothalamic-pituitary-adrenal stress response system alongside catecholamine and neuropeptide abnormalities that collectively establish the neurobiological substrate of trauma-related symptoms. Genetic and epigenetic research demonstrates polygenic vulnerability combined with gene-environment interactions that determine individual susceptibility. Clinical heterogeneity is illustrated through the dissociative subtype featuring depersonalization and derealization experiences and the complex PTSD formulation recognized in ICD-11 that captures developmental and relational sequelae of prolonged trauma. Treatment frameworks emphasize first-line pharmacologic agents including serotonin reuptake inhibitors and serotonin-norepinephrine reuptake inhibitors alongside specific agents addressing particular symptom profiles, combined with evidence-based psychotherapeutic modalities including trauma-focused cognitive-behavioral therapy, prolonged exposure, cognitive processing therapy, and eye movement desensitization and reprocessing, with recognition of early intervention importance and integration of resilience-enhancing and social support strategies across diverse populations.