Figure 1. A-D. Frequency of Diagnosis-Specific (A-C) and Broad Reviews (i.e., Covering More Than One FSS Diagnosis and SSD) (D) Per Year of Publication Since 1990, Divided Into Narrative Reviews, Systematic Reviews Without and Systematic Reviews With Meta-Analyses.

Note. Reviews focusing on somatic symptom disorder are summarised under reviews with a broad diagnostic concept. FMS = fibromyalgia syndrome; FSS = functional somatic syndrome; IBS = irritable bowel syndrome; CFS / ME = chronic fatigue syndrome / myalgic encephalomyelitis; SSD = somatic symptom disorder.