Further psychometric testing of a brief personality scale to measure vulnerability to postpartum depression.

The Vulnerability Personality Style Questionaire (VPSQ), a 9-item self-report personality scale, was developed to identify women at-risk for postpartum depression due to personality vulnerability. Preliminary research with this scale suggests it has satisfactory psychometric properties. The purpose of this methodological study was to further examine the psychometric properties of the VPSQ in a sample of Canadian women. As part of a longitudinal study, women completed postal questionnaires at 1, 4, and 8 weeks postpartum that included the VPSQ, Edinburgh Postnatal Depression Scale, Rosenburg Self-Esteem Scale, and Perceived Stress Scale. Five hundred and ninety-four women returned questionnaires suitable for analysis. The Cronbach's alpha coefficient for the VPSQ was 0.67 and significant correlations between the VPSQ and self-esteem (r = 0.58) and perceived stress (r = 0.55) scales were found, providing evidence for construct validity. In a logistic regression analysis, VPSQ was predictive of developing depressive symptomatology 1, 4 and 8 weeks postpartum; an increase of one point on the VPSQ increased the risk of developing postpartum depression 1.3 fold. The results from this study support the overall utility of the VPSQ. As such, this brief instrument is ready to assist in the identification of women at-risk of developing postpartum depression such that appropriate secondary preventive or treatment interventions may be initiated.