Assessing psychopathology in bariatric surgery candidates: discriminant validity of the SCL-90-R and SCL-K-9 in a large sample of patients

PURPOSE: Pre-surgical psychosocial evaluation of bariatric surgery (BS) patients should identify psychiatric issues that could worsen after surgery and those requiring additional ongoing intervention. In this view, the use of reliable, appropriate and concise evaluating instruments is of critical importance. The aim of the present study was to investigate the clinical utility of both the Symptom Checklist 90-Revised (SCL-90-R) and its brief unidimensional version, the so-called Symptom-Checklist-K-9 (SCL-K-9) in detecting the presence of psychiatric disorders among bariatric surgery (BS) candidates. METHODS: Seven-hundred-and-ninety-eight BS candidates (563 women and 235 men; mean age: 44.15 ± 11.45) were enrolled in the present study. All participants underwent a full psychiatric interview and were administered the SCL-90-R. RESULTS: Three-hundred-and-sixty-two patients (45.4%) met the criteria for a diagnosis of at least one psychiatric disorder and ninety-nine patients (12.4%) had psychiatric comorbidities. In the current sample, 219 patients (27.4%) met the criteria for binge eating disorders (BED), 158 (19.8%) met the criteria for major depressive disorder (MDD), and 67 (8.4%) met both criteria. A receiver operating characteristic (ROC) curves procedure showed that both the SCL-90-R and the SCL-K-9 satisfactorily categorize patients with any psychiatric disorder, both BED and MDD (area under the ROC curve ≥ 0.70, p < 0.001). CONCLUSION: Our results suggest that the SCL-90-R and the SCL-K-9 may represent first-level screening tests identifying at-risk patients, eligible for a more expensive or time-consuming clinical assessment. LEVEL OF EVIDENCE: Level V, cross-sectional, descriptive study. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s40519-020-01068-2) contains supplementary material, which is available to authorized users.