Magister Psychologiae - MPsych / Exposure to severe trauma and resulting PTSD affects individuals of all ages, cultures and geographical areas. Epidemiological surveys reveal that approximately one third of the general population is exposed to a traumatic event at some point in their lives. From the people exposed to a traumatic event about 10% will develop PTSD. Compelling evidence further suggests that the PTSD prevalence in South Africa is even higher,especially among the youth, and has thus been identified as a significant public health concern. In order to adequately address the diverse effects of PTSD,reliable and valid instruments diagnosing PTSD are required. It is a further imperative that these instruments are adapted to the specific context in which they will be utilized. This study thus focused on assessing the psychometric properties (factorial validity and internal consistency) of the Child PTSD Checklist in a sample of treatment-seeking children adolescents in the Western Cape. For the purpose of this study secondary data from a larger, longitudinal study investigating PTSD in children and adolescents was utilized.The preliminary study employed a quantitative research design in order to obtain data from the participants. The sample comprised of 200 children and adolescents between the ages of 8 and 18 years that were selected from the Youth Stress Clinic. In terms of the psychometric properties the scale demonstrated excellent internal consistency(Cronbach’s alpha = 0.93). Exploratory factor analysis revealed a three factor structure(anxiety and avoidance, anger and dissociation, depressive symptoms) which accounted for 41,96 % of the total variance. In conclusion, the Child PTSD Checklist appears to be a promising tool for assessing PTSD in trauma-exposed youth in clinic settings, however further studies are needed to address its broader utility.

The purpose of this quantitative study was to examine whether the post-deployment screening instrument currently utilized to assess active-duty Marines for symptoms of PTSD upon their return from a combat deployment can be solely relied upon to accurately assess for PTSD. Additionally, this study sought to compare the number of Marines who have sought trauma-related mental health treatment based on their answers on the Post-Deployment Health Assessment (PDHA) to the number who have sought trauma-related mental health treatment based on their answers on their PTSD Checklist â?? Military Version (PCL-M). The participants in this study were comprised of a sample of active-duty Marines that had recently returned from a combat deployment. A quantitative secondary data analysis used Item Response Theory (IRT) to examine the answers provided by the participants on both the PDHA and PCL-M. Both instruments proved to be effective when assessing symptoms of PTSD and the participants identified as having symptoms of PTSD were referred for mental health services as required. According to the results, more Marines were identified as having symptoms of PTSD using both assessment instruments (PDHA and PCL-M) compared to those identified using just the PDHA. The result was a better understanding of predictors of Marines who may later develop PTSD. The results of this study can also assist the Marine Corps with its post-deployment screening for symptoms of PTSD which in turn can provide appropriate mental health referrals for Marines if deemed appropriate.

The purpose of this quantitative study was to examine whether the post-deployment screening instrument currently utilized to assess active-duty Marines for symptoms of PTSD upon their return from a combat deployment can be solely relied upon to accurately assess for PTSD. Additionally, this study sought to compare the number of Marines who have sought trauma-related mental health treatment based on their answers on the Post-Deployment Health Assessment (PDHA) to the number who have sought trauma-related mental health treatment based on their answers on their PTSD Checklist - Military Version (PCL-M). The participants in this study were comprised of a sample of active-duty Marines that had recently returned from a combat deployment. A quantitative secondary data analysis used Item Response Theory (IRT) to examine the answers provided by the participants on both the PDHA and PCL-M. Both instruments proved to be effective when assessing symptoms of PTSD and the participants identified as having symptoms of PTSD were referred for mental health services as required. According to the results, more Marines were identified as having symptoms of PTSD using both assessment instruments (PDHA and PCL-M) compared to those identified using just the PDHA. The result was a better understanding of predictors of Marines who may later develop PTSD. The results of this study can also assist the Marine Corps with its post-deployment screening for symptoms of PTSD which in turn can provide appropriate mental health referrals for Marines if deemed appropriate.

Contexte théorique : Au Canada, la prévalence du trouble de stress post-traumatique (TSPT) serait de 9,2%. Plusieurs questionnaires ont été développés pour mesurer les symptômes du TSPT dont le PTSD Checklist For DSM-5 (PCL-5). Ce questionnaire autorapporté a été validé à plusieurs reprises avec des échantillons non-cliniques ou militaires. Toutefois, le PCL-5 n’a jamais été validé avec un échantillon clinique et civil. Aussi, le nombre idéal de facteur du PCL-5 reste toujours à être démontré. Objectif : Cette étude vise à établir la validité de construit du PCL-5 d’un échantillon clinique et civil de 132 participants aux prises avec un TSPT. Les 3 principales structures factorielles seront analysées de façon à retenir celle qui présente les meilleurs résultats. Méthodologie : Les structures factorielles ont été mesurées avec des analyses factorielles confirmatoires et des analyses bifactorielles. La consistance interne a été mesurée à partir du coefficient Oméga de McDonald. La validité convergente et divergente a été mesurée par des corrélations de Pearson avec d’autres construits. Résultats : Au niveau des indices d’ajustement, le modèle à 7 facteurs a obtenu les meilleurs résultats. Sur le plan de la fidélité et sur celui de la validité convergente et divergente, le modèle à 4 facteurs possède les résultats les plus optimaux. Discussion : Globalement, le modèle à 4 facteurs est le plus approprié pour le PCL-5. De plus, les modèles à 6 et 7 facteurs présentent quelques lacunes sur le plan méthodologique et statistique. Finalement, le PCL-5 est un questionnaire valide et fidèle pour une population clinique et civile. / Background: In Canada, the prevalence of post-traumatic stress disorder (PTSD) is estimated to be 9.2%. Several questionnaires have been developed to measure the symptoms of PTSD including the PTSD Checklist For DSM-5 (PCL-5). This questionnaire has been validated several times with non-clinical or military samples. However, PCL-5 has never been validated with a clinical and civilian sample. Also, the ideal factor number of PCL-5 has yet to be demonstrated. Objective: This study aims to establish the construct validity of PCL-5 in a clinical and civilian sample of 132 participants with PTSD. The 3 main factor structures will be analyzed in order to retain the one that presents the best results. Methodology: Factor structures were measured with confirmatory factor analyzes and bifactor analyzes. Internal consistency was measured from McDonald's Omega coefficient. Convergent and discriminant validity was measured by Pearson correlations with other constructs. Results: In terms of fit statistics, the 7-factor model obtained the best results. In terms of reliability and convergent and divergent validity, the 4-factor model has the most optimal results. Discussion: Overall, the 4-factor model is the most appropriate for the PCL-5. In addition, the 6 and 7 factor models have some methodological and statistical limitations. Finally, the PCL-5 is a valid and reliable questionnaire for a clinical and civilian population.