Evaluation of factor structure, validity and reliability indices of Vulnerable Personality Style Questionnaire in the Iranian sample and its effect on postpartum depression

The Vulnerable Personality Style Questionnaire (VPSQ) is a self-report scale designed to identify women at risk for postpartum depression due to personality vulnerability. Therefore, the purpose of this study was to investigate factor structure, validity and reliability indicators of the Vulnerable Personality Questionnaire and its effect on postpartum depression in Iranian women. The design of this research was cross-sectional-descriptive. The statistical population of this study were women with postpartum depression in Isfahan. Three hundred women with postpartum depression were randomly selected from women with postpartum depression in Isfahan. They were selected based on their performance on the following questionnaires; the Vulnerable Personality Style Questionnaire of Boyce et al. (2004), and Edinburgh Postnatal Depression Scale (1978). The results of exploratory factor analysis (EFA) showed that the questionnaire has a two-factor structure. Cronbach's alpha coefficient of the two dimensions of vulnerability and organization was 0.87 and 0.705 respectively, which showed that the reliability of the questionnaire is suitable. Hierarchical regression analysis showed that after controlling demographic variables (age, mother's education, father's occupation and family income), vulnerable personality has a significant effect on postpartum depression (β = 0.503, p < 0.001). It seems that the Vulnerable Personality Style Questionnaire has appropriate psychometric indices and this tool can be used to predict postpartum depression in women, and prevent its negative consequences