Can scent-detection dogs detect the stress associated with trauma cue exposure in people with trauma histories? A proof-of-concept study

In recent studies of the structure of affect, positive and negative affect have consistently emerged as two dominant and relatively independent dimensions. A number of mood scales have been created to measure these factors; however, many existing measures are inadequate, showing low reliability or poor convergent or discriminant validity. To fill the need for reliable and valid Positive Affect and Negative Affect scales that are also brief and easy to administer, we developed two 10-item mood scales that comprise the Positive and Negative Affect Schedule (PANAS). The scales are shown to be highly internally consistent, largely uncorrelated, and stable at appropriate levels over a 2-month time period. Normative data and factorial and external evidence of convergent and discriminant validity for the scales are also presented.

The Posttraumatic Stress Disorder Checklist (PCL) is a widely used DSM-correspondent self-report measure of PTSD symptoms. The PCL was recently revised to reflect DSM-5 changes to the PTSD criteria. In this article, the authors describe the development and initial psychometric evaluation of the PCL for DSM-5 (PCL-5). Psychometric properties of the PCL-5 were examined in 2 studies involving trauma-exposed college students. In Study 1 (N = 278), PCL-5 scores exhibited strong internal consistency (α = .94), test-retest reliability (r = .82), and convergent (rs = .74 to .85) and discriminant (rs = .31 to .60) validity. In addition, confirmatory factor analyses indicated adequate fit with the DSM-5 4-factor model, χ2 (164) = 455.83, p < .001, standardized root mean square residual (SRMR) = .07, root mean squared error of approximation (RMSEA) = .08, comparative fit index (CFI) = .86, and Tucker-Lewis index (TLI) = .84, and superior fit with recently proposed 6-factor, χ2 (164) = 318.37, p < .001, SRMR = .05, RMSEA = .06, CFI = .92, and TLI = .90, and 7-factor, χ2 (164) = 291.32, p < .001, SRMR = .05, RMSEA = .06, CFI = .93, and TLI = .91, models. In Study 2 (N = 558), PCL-5 scores demonstrated similarly strong reliability and validity. Overall, results indicate that the PCL-5 is a psychometrically sound measure of PTSD symptoms. Implications for use of the PCL-5 in a variety of assessment contexts are discussed.

Data were obtained on the general population epidemiology of DSM-III-R posttraumatic stress disorder (PTSD), including information on estimated life-time prevalence, the kinds of traumas most often associated with PTSD, sociodemographic correlates, the comorbidity of PTSD with other lifetime psychiatric disorders, and the duration of an index episode. Modified versions of the DSM-III-R PTSD module from the Diagnostic Interview Schedule and of the Composite International Diagnostic Interview were administered to a representative national sample of 5877 persons aged 15 to 54 years in the part II subsample of the National Comorbidity Survey. The estimated lifetime prevalence of PTSD is 7.8%. Prevalence is elevated among women and the previously married. The traumas most commonly associated with PTSD are combat exposure and witnessing among men and rape and sexual molestation among women. Posttraumatic stress disorder is strongly comorbid with other lifetime DSM-III-R disorders. Survival analysis shows that more than one third of people with an index episode of PTSD fail to recover even after many years. Posttraumatic stress disorder is more prevalent than previously believed, and is often persistent. Progress in estimating age-at-onset distributions, cohort effects, and the conditional probabilities of PTSD from different types of trauma will require future epidemiologic studies to assess PTSD for all lifetime traumas rather than for only a small number of retrospectively reported "most serious" traumas.