Testing the Validity of the K6 in Detecting Major Depression and PTSD Among Jailed Women

Abstract

Despite high prevalence rates of mental illness, jails often lack validated measures for detecting it, and many of the screening instruments used do not adequately identify depression and trauma-related disorders in women. The authors assessed the validity of the K6 in identifying major depression and PTSD among 515 jailed women, comparing it to two valid and reliable screening tools, the PHQ-9 and the Short Screening Scale for DSM-IV PTSD. The K6 identified 37% of women as having serious mental illness using the customary cut score of 13, with an ROC-AUC value of .92 in detecting major depression or PTSD. However, this cut score misclassified a substantial proportion of women; therefore, a modification of this score may be warranted. Lowering this cut score would increase the number of women identified but may be justified by incarcerated women’s high rates of exposure to trauma and the consequences of unmet mental health needs.