Comparing the diagnostic concepts of ICD-10 somatoform disorders and DSM-5 somatic symptom disorders in patients from a psychosomatic outpatient clinic.

OBJECTIVE: The reconceptualization of somatic symptom and related disorders in DSM-5 led to numerous consequences in terms of prevalence and affected patient populations. The present study aimed to investigate frequencies of ICD-10 somatoform disorders and DSM-5 somatic symptom disorders, and how the respective diagnostic groups differ in terms of sociodemographic and psychopathological characteristics. It discusses the usefulness and reliability of the new diagnostic criteria.

METHOD: Patients from a German psychosomatic outpatient clinic (n = 438) completed self-report questionnaires on depression (PHQ-9), anxiety (GAD-7), symptom burden (PHQ-15), psychological distress (SSD-12), and quality of life (SF-12). ICD-10 diagnoses were provided by treating clinicians, DSM-5 diagnoses were assessed via semi-structured telephone interviews. The prevalence of somatic symptom disorders and their overlap with ICD-10 somatoform disorders was evaluated. Comparisons between patients with either diagnosis were drawn.

RESULTS: More than half of the sample (n = 239, 54.6%) fulfilled the criteria for a somatic symptom disorder. Compared to patients fulfilling ICD-10 criteria only, patients with a somatic symptom disorder presented higher levels of symptom related distress (p = .045), health related anxiety (p = .004), general anxiety (p = .011), and lower mental health-related quality of life (p = .015), while patients with ICD-10 somatoform disorders reported a lower physical health-related quality of life (p = .031).

CONCLUSION: DSM-5 criteria included more patients than ICD-10 somatoform disorders in our sample. Patients diagnosed with a somatic symptom disorder appear to be more severely impaired in terms of general and health-related anxiety and psychological distress associated to their somatic symptoms, especially when diagnosed with a severe form of somatic symptom disorder.