I work extensively in the area of behavioral health and found the recent article by Wolf et al about Somatic Symptom Disorder to be very interesting.
I too take issue with diagnostic criteria of Somatic Symptom Disorder (SSD) including: distressing somatic symptoms + excessive thoughts, feelings, and behaviors in response to these symptoms.
I’m not entirely sure who is to judge (other than the clinician) that the thoughts are excessive (exactly what thoughts?, when?, context?), or that the behaviors in response to these symptoms are of such degree as to attain diagnostic significance.
Consider the following that may compromise validity:
- Patient is referred or self-refers and presents with history during the initial intake. There may or may not be records, and if there are, the records may be thin and very recent depending on onset.
- Criterion C of SSD provides a time frame of “typically more than 6 months.” Assessing under this time frame would require a R/O specifier, and this specifier cannot disappear magically without actually assessing and supporting the basis for ruling SSD in.
- How to assess? Subjective self-report? Collateral sources? Objective measures? Wolfe et al used the Patient Health Questionnaire-15 (PHQ-15).
- Consider that the PHQ-15 is “characterized as a measure of somatic symptom severity rather than a diagnostic instrument for somatoform disorders.” And somatoform disorders are DSM-IV-TR. Seehttp://www.psychosomaticmedicine.org/content/64/2/258.full.pdf+html
- PHQ-15 is a brief self-report tool and has no validity scale. It is a 3-point scale, and does not provide typical five-level Likert items with a neutral middle option such as:
- Strongly disagree
- Neither agree nor disagree
- Strongly agree
- Tests validated for DSM-5?
- Under Risk and Prognostic Factors: “Somatic symptom disorder is more frequent in individuals with few years of education and low socioeconomic status, and those who recently experienced stressful life events.” Do these, therefore, result in increased false positives?
- Under Culture-Related Diagnostic Issues, it is noted: “there are differences in somatic symptoms among cultures and ethnic groups”, and “somatic symptoms may have special meanings and shape patient-clinician interactions in the particular cultural contexts.” What? How? How to assess? And how to distinguish satisfying diagnostic criteria among one particular culture or ethnic group and another?
- Differential diagnosis lists 9 categories. Add to that the erosion to validity of frequent comorbodity.
I don’t take issue with the conclusions (although the PHQ-15 as the sole objective measure is weak). I find a number of validity-compromising extraneous and confounding variables and possibility of selection bias.