Exploring antenatal factors in postnatal depression : a thesis presented in partial fulfilfment of the requirements for the degree of Master of Arts in Psychology at Massey University, Albany, New Zealand
Up to 20% of all new mothers may suffer from postnatal depression. This amounts to around 3,500 mothers each year in Auckland alone. The effects of postnatal depression are far reaching and can impact detrimentally on the lives of mothers and those close to them. To understand more about postnatal depression, British researchers Cooper, Murray, Hooper, and West (1996) developed a measure for identifying antenatally women who may be at risk of developing postnatal depression. The present study examined the predictive validity of Cooper et al.'s antenatal index in identifying mothers likely to develop postnatal depression in a New Zealand population. Ninety-eight Auckland mothers completed antenatal and postnatal questionnaires that included Cooper et al.'s predictive index, the GHQ-12 and the Edinburgh Postnatal Depression Scale. Results suggested that the predictive ability of Cooper et al.'s measure improved when including an antenatal measure of general wellbeing (the GHQ-12) into the regression equation. The results suggested that 60% of the variance in postnatal depression scores was attributed to the antenatal predictive index. The GHQ-12 added to the predictive ability by explaining an additional 19% of the variance in postnatal depression scores. Discriminant analysis showed that the percentage of cases correctly classified into depressed and non-depressed was 66% and the sensitivity, specificity and positive predictive value of the antenatal measures achieved comparable findings to that of Cooper et al. Recommendations for future research include using a different methodological approach and investigating the predictive power of the General Health Questionnaire further.