Chapter 70: Anxiety Disorders and Post-Traumatic Stress Disorder

Anxiety disorders, affecting approximately one-third of American adults and adolescents during their lifetime, are distinguished from normal stress responses by their persistent nature and substantial impairment of daily functioning. The chapter details the major anxiety disorder categories including specific phobias, social anxiety disorder, generalized anxiety disorder, panic disorder, and agoraphobia, each with distinct prevalence rates and clinical presentations. Understanding the underlying vulnerability factors is essential; anxiety disorders result from complex interactions among genetic predisposition, environmental stressors, developmental experiences, and neurobiological systems involving key brain structures like the amygdala and the hypothalamic-pituitary-adrenal axis, along with dysregulation of neurotransmitters including serotonin, norepinephrine, and gamma-aminobutyric acid. Systematic screening using validated instruments such as the generalized anxiety disorder scale and combined symptom screeners enables early identification while ruling out medical causes and substance-related etiologies. Generalized anxiety disorder, characterized by six months or longer of uncontrollable excessive worry, responds well to serotonin reuptake inhibitors and serotonin-norepinephrine reuptake inhibitors as pharmacological first-line options, complemented by cognitive behavioral therapy and mindfulness interventions. Panic disorder presents with recurrent unexpected panic attacks coupled with anticipatory anxiety, while specific phobias benefit primarily from psychotherapy with exposure-based techniques rather than medication except in acute situations. Post-traumatic stress disorder, developing after exposure to actual or threatened trauma and persisting beyond thirty days, manifests across four symptom clusters including intrusive thoughts, avoidance behaviors, negative cognitive and mood alterations, and hyperarousal changes; treatment prioritizes trauma-focused psychotherapy modalities such as prolonged exposure therapy and cognitive processing therapy alongside pharmacological agents. The chapter emphasizes specialized considerations including pharmacogenetic testing for personalized medication selection, careful medication management in geriatric populations to minimize polypharmacy risks, and developmentally appropriate assessment in pediatric populations, alongside the importance of therapeutic alliance and patient education regarding delayed symptom relief and sustained follow-up.