L'inquiétude excessive, caractéristique centrale du trouble d'anxiété généralisée (TAG), entraîne plusieurs conséquences négatives pour l'individu. Jusqu'à maintenant, les cliniciens et les chercheurs ne disposaient d'aucun instrument français, dûment validé, pour mesurer la tendance à s'inquiéter. Cet article présente les résultats de trois études qui établissent les propriétés psychométriques d'une traduction française du PSWQ, le Questionnaire sur les inquiétudes de Penn State (QIPS). L'étude 1 décrit les étapes de traduction du questionnaire et vérifie sa structure factorielle, sa cohérence interne, la qualité de ses items et sa validité convergente auprès de participants issus de la population non clinique. L'étude 2 évalue sa stabilité temporelle de même que sa validité convergente et discriminante. Enfin, l'étude 3 mesure la cohérence interne du QIPS, la qualité de ses items et sa validité convergente et discriminante auprès d'un échantillon clinique souffrant d'un TAG. L'ensemble des résultats obtenus démontre que le QIPS présente d'excellentes qualités psychométriques auprès des populations clinique et non clinique. Ce nouvel outil s'avère un instrument de choix pour les cliniciens et les chercheurs qui désirent évaluer efficacement la tendance à s'inquiéter chez les adultes francophones.

Excessive worry, which is the central feature of Generalized Anxiety Disorder (GAD), is recognized as an important clinical phenomenon with many negative consequences on people's health. For example, studies report that excessive worry is associated with higher frequencies of work absenteeism and medical consultations, increased risk of other anxiety disorders, depression, heart disease, diabetes and cancer. It is thus imperative to develop effective measures to assess worry among adult. Until now, no measures were available in French for the practitioners and researchers to evaluate the tendency to engage in excessive and uncontrollable worry. One of the most frequently used questionnaires to assess worry in English is The Penn State Worry Questionnaire (PSWQ). This self-report measure has been widely studied and has shown excellent psychometric properties among the non-clinical and clinical populations. This manuscript presents the results of three studies evaluating the psychometric properties of a French Translation of the PSWQ, the Questionnaire sur les Inquiétudes de Penn State (QIPS). The first study includes the translation procedures used to create the French version of the questionnaire, the factorial structure, the internal consistency, the quality of the items, and the convergent validity among non-clinical participants. The second study examines the temporal stability, and the convergent and divergent validity of the questionnaire. Finally, the third study investigates the internal consistency, the quality of the items, and the convergent and divergent validity of the questionnaire among GAD patients. Study 1 . This study describes the translation procedures used to create the QIPS, the factorial structure, the internal consistency, the quality of the items, and the convergent validity among non-clinical participants. The French version was translated by a group of clinical psychologists with the assistance of a professionnal translator and a linguist. A back translation procedure was also conducted. Finally, a pilot study confirmed the intelligibility of the questionnaire. French-speaking university students (N = 352) completed a battery of questionnaires during a lecture. The questionnaires were : The Questionnaires sur les Inquiétudes de Penn State , the Intolerance of Uncertainty Questionnaire, the Cognitive Avoidance Questionnaire, the Why Worry Questionnaire-Revised, and the Social Problem-Solving Inventory-Revised. The statistical analyses reveal that the QIPS shows an appropriate factorial structure, an excellent internal consistency and a very good convergent validity. This French Questionnaire thus seems to be suitable to assess the tendency to worry among the non-clinical population. Study 2 . This second study examines the temporal stability, and the convergent and divergent validity of the QIPS. The sample includes 95 French-speaking University students who volunteered to complete the QIPS and the Beck anxiety Inventory. Two self-rating questions were also asked to evaluate the percentage of time spent worrying and to what extent does worrying causes a problem. Eighty-six students participated at the second administration of the questionnaires, four weeks later. The results indicate that the QIPS is very stable over time, thus supporting its temporal stability. Different correlations confirm its convergent and divergent validity. It is concluded that the QIPS is a suitable measure of worry in a non-clinical population. Study 3 . This study investigates the internal consitency, the quality of the items, and the convergent and divergent validity of the questionnaire among GAD patients. Seventy-seven GAD patients, as defined by the Diagnostic and Statistical Manual of Mental disorders, fourth edition (DSM IV), participated in this study. They completed the QIPS, the Worry Domains Questionnaire, The Worry and Anxiety Questionnaire, the Intolerance of Uncertainty Questionnaire, the Beck Anxiety Inventory, the Beck Depression Inventory, and a daily diary of differents aspects of worry. The results reveal that the QIPS has an excellent internal consistency, a very good convergent and divergent validity. The QIPS thus seems to be suitable to assess the tendency to worry among GAD patients. Conclusion. The overall results presented in these studies confirm the excellent psychometric properties of the QIPS. This French questionnaire is a useful tool for clinicians and researchers to assess the tendency to worry among non-clinical and clinical populations.