Chapter 18: Somatic Symptom and Related Disorders

The historical conceptualization of these presentations has evolved substantially, moving from earlier diagnostic frameworks such as hysteria and hypochondriasis toward the DSM-5 approach, which emphasizes the maladaptive cognitive patterns, affective dysregulation, and behavioral responses surrounding somatic symptoms rather than requiring them to be medically unexplained. The chapter comprehensively addresses multiple disorder presentations within this spectrum, including somatic symptom disorder where patients experience excessive thoughts and behaviors focused on their physical symptoms, illness anxiety disorder characterized by preoccupation with serious illness in the presence of minimal or absent symptoms, and conversion disorder which manifests as functional neurological impairments without identifiable neurological pathology. Additional conditions covered include factitious disorder and the significant impact of psychological factors on existing medical conditions. Epidemiological data reveals substantial prevalence across diverse cultural contexts, with particularly elevated rates among women and adolescent populations, frequently co-occurring with depression and anxiety disorders. The chapter presents an integrated biopsychosocial etiological model incorporating genetic vulnerability, neurobiological mechanisms including altered central sensitivity and interoceptive processing, early life adversity, learned maladaptive illness behaviors, cultural conceptualizations of distress, and alexithymia as significant contributing factors. Clinical presentations demonstrate considerable variability ranging from mild functional impairment to severe chronic disability accompanied by excessive healthcare utilization. Evidence-based treatment emphasizes cognitive-behavioral therapy as the primary intervention, supported by psychoeducational approaches and consistent primary care coordination, with pharmacotherapy targeting comorbid psychiatric symptoms rather than addressing somatic complaints directly. The overarching clinical framework stresses the importance of establishing therapeutic alliance, avoiding unnecessary diagnostic investigations, and implementing patient-centered care that validates subjective experience while systematically addressing underlying psychological mechanisms.