Complexity Assessed by the INTERMED in Patients With Somatic Symptom Disorder Visiting a Specialized Outpatient Mental Health Care Setting: A Cross-sectional Study

Psychosomatics. 2017 Jul-Aug;58(4):427-436. doi: 10.1016/j.psym.2017.02.008. Epub 2017 Feb 21.


Background: Somatic symptom disorders (SSD), a new classification in the Diagnostic and Statistical Manual of Mental Disorders, fifth edition is associated with problematic diagnostic procedures and treatment that lead to complex care. In somatic health care, the INTERMED has been used to assess levels of complexity; however, in SSD this instrument has not yet been applied.

Objective: This study aims to explore complexity in patients with SSD using the INTERMED, hereby contributing to an increased comprehension of this new patient group.

Method: In this cross-sectional study, the INTERMED was used to assess complexity in outpatients with SSD at the Clinical Centre of Excellence for Body, Mind, and Health (The Netherlands), along biologic, psychologic, social, and health care domains. This was done retrospectively with patient files from consecutive patients from 2011 until 2015.

Results: In the total SSD sample (N = 187), 63% was female, the mean age (standard deviation) was 42 (±12.4) years, with an average educational level. The mean INTERMED score was 23.5 indicating high overall complexity in this population. A high proportion of our sample (69%) scored as highly complex (>20). High complexity was associated with higher depression and anxiety scores, but not with a higher number of physical symptoms.

Conclusions: This study demonstrates that patients with SSD form a high-complex group, with higher scores compared with literature about multiple sclerosis, rheumatoid arthritis, or patient waiting for a liver transplant. INTERMED outcomes indicate a need for extensive diagnostic procedures and integrated multidisciplinary care for patients with SSD. Attention should especially be paid to mental disorders (depression and anxiety), given their association with high complexity.

Keywords: Complexity; INTERMED; Mental health care; Somatic symptom disorder.

Publication types

  • Observational Study

MeSH terms

  • Adult
  • Cross-Sectional Studies
  • Female
  • Hospitals, Psychiatric
  • Humans
  • Male
  • Medically Unexplained Symptoms
  • Netherlands
  • Outpatients*
  • Reproducibility of Results
  • Retrospective Studies
  • Severity of Illness Index
  • Somatoform Disorders / diagnosis*
  • Surveys and Questionnaires*