Yahui Zhang, Meijing Feng, Rui Ma, Qiuyan Xue, Xue Li, Fangming Liu
Body-focused repetitive behaviors (BFRBs) and somatic symptom disorder (SSD) are classified in different chapters in DSM-5. The former is characterized by repetitive body-focused actions, whereas the latter is characterized by distressing somatic symptoms accompanied by excessive thoughts, feelings, or behaviors related to those symptoms. Although parallel evidence has accumulated in each domain, direct comparative studies between BFRBs and SSD remain lacking. This gap arises partly from diagnostic separation, divergent research paradigms, and inconsistent terminology. The present mini review therefore proposes a hypothesis-generating conceptual framework in which difficulty identifying feelings and altered interoceptive processing may represent candidate processes relevant to both conditions. However, the strength of evidence is asymmetric. In SSD, interoceptive response bias has been examined using objective and signal-detection-based paradigms, whereas in BFRBs direct objective evidence remains limited. Accordingly, the proposed BFRB pathway should be regarded as a tentative hypothesis rather than an established mechanism. We further outline operational definitions, methodological considerations, and exploratory research questions for future comparative studies.