[Evaluation of Post-traumatic Stress Disorder: validation of a measure, the PCLS]

Post-Traumatic Stress Disorder (PTSD) is a psychiatric disorder frequently found in psychiatric clinic and in the population of victims of traumatic events. PTSD, characterized by an intense fear, helplessness or horror, resulting from exposure to a traumatic event, is clinically manifested with three main syndromes: reexperiencing, avoidance behavior and numbing of emotion, and physiological hyperarousal. The Post-Traumatic Checklist Scale (PCLS) is a brief and self-report questionnaire for evaluating the severity of three main syndromes of PTSD. The scale can be divided into three sub-scores corresponding to the three main syndromes of the disorder: reexperiencing (items 1-5), avoidance (items 6-12) and hyperarousal (items 13-17). The validation studies in English version (Weathers et al., 1993, Blanchard et al., 1996) and French version (Ventureyra et al., 2001) showed that the PCLS possesses good psychometric properties. But the discriminating validation with another pathological group and the sensitivity of the scale to change of treatment have not yet been studied up to now. The aim of this study is the validation of the French version of the PCLS in Post-Traumatic Stress Disorder (PTSD) subjects compared with subjects suffering from other anxiety disorders and non-clinical subjects. The sensitivity of the PCLS after a cognitive behavioral therapy (CBT) for PTSD was studied for the first time. Fifty-seven outpatients suffering from PTSD according to DSM IV criteria, 23 patients suffering from other anxiety disorders and 28 non-clinical subjects were included in this study. All subjects were assessed with the PCLS. The Beck Depression Inventory--13 items (BDI-13) and the Fear Questionnaire (FQ) were used for the two groups of patients. Fifty-five PTSD patients were administered the PCLS twice over an interval of one to two weeks without any intervention in order to determine the test-retest reliability of the PCLS. And 24 PTSD patients were reassessed with the PCLS after 16 sessions of cognitive behavioral therapy (CBT) in order to study the sensitivity to treatment of the PCLS. The CBT technique for PTSD consisted of relaxation, exposition, recital, cognitive restructuration and stress management. The total score and the subscores on the PCLS were found to be significantly higher in PTSD patients than in two control groups: suffering from other anxiety disorders subjects (61.2/41.4, p<0.0001) and non-clinical subjects (61.2/28.8, p<0.0001). The correlation between the PCLS total score and the others measures showed that the PCLS correlated significantly with the depression measure, the BDI-13 (p<0.001), and the sub-scores of Fear Questionnaire (agoraphobia: p<0.001; anxiety-depression: p<0.001; distress: p<0.001), but not with the social phobia sub-score of the FQ. The PCLS showed a satisfactory test-retest reliability in 55 patients (the total score: r=0.75, p<0.0001; the sub-score of reexperiencing: r=0.844, p<0.0001; the sub-score of avoidance: r=0.702, p<0.0001; the sub-score of hyperarousal: r=0.712, p<0.0001). The t-test showed that the total score of the PCLS was significantly reduced in 24 patients after 16 sessions of CBT (the mean gain=13.1, t=5.63, p<0.0001). The results of our study confirm that the PCLS possesses good empirical and discriminating validity and a good sensitivity. The fact that the PTSD patients reported significantly higher total scores on the PCLS and its three subscores than other anxiety disorder subjects and non-clinical subjects indicates that the PCLS differentiates well the patients presenting PTSD from other anxiety disorder subjects and non-clinical subjects. The PCLS total score also correlates significantly with the other measures of psychopathology used in the study, such as measures of phobia (the Fear Questionnaire agoraphobia subscale), depression (the Beck Depression Inventory -13) and distress (the Fear Questionnaire distress subscale). This may be explained by the fact that some PTSD symptoms overlap with those of depression and of anxiety or phobia. The PCLS showed anxiety or phobia. The PCLS showed a satisfactory test-retest reliability. The PCLS is therefore a valid and effective measurement of PTSD. It may be a useful tool for screening and assessing PTSD in clinical practice and research in psychiatry.