The SIMS Screen for feigned mental disorders: the development of detection-based scales

Time-efficient screens for feigned mental disorders (FMDs) constitute important tools in forensic assessments. The Structured Inventory of Malingered Symptomatology (SIMS) is a 75-item true-false questionnaire that has been extensively studied as an FMD screen. However, the SIMS scales are not based on established detection strategies, and only its total score is utilized as a feigning screen. This investigation develops two new feigning scales based on well-established detection-strategies: rare symptoms (RS) and symptom combinations (SC). They are studied in a between-subjects simulation design using inpatients with partial-malingering (i.e., patients with genuine disorders asked to feign greater disabilities) conditions. Subject to future cross-validation, the SC scale evidenced the highest effect size (d=2.01) and appeared the most effective at ruling out examinees, who have a high likelihood of genuine responding.