Somatization: a critical review of conceptual and methodological issues.

Despite its apparent clinical importance and the extensive research that has been conducted in the past decades, somatization remains a complex concept. Two distinct ways of looking at somatization can be distinguished: somatization as a phenomenon that is secondary to psychological distress (presenting somatization) and somatization as a primary phenomenon characterized by medically unexplained symptoms (functional somatization). The literature was analyzed in terms of this distinction and a selective review was conducted, focusing on a critical analysis of conceptual and methodological issues related to presenting and functional somatization. A number of measurement issues related to somatization in general were also highlighted. On the basis of the available data, the strengths and weaknesses of different concepts are pointed out. Conclusions are formulated regarding which concepts or approaches might be useful both clinically and from a research perspective. Finally, a number of suggestions for future research are offered.