This study investigates the risk factors for antenatal depression, postnatal depression, and parenting stress. The researchers recruited 367 primipara and multipara women from two major hospitals in Melbourne, Australia, as part of the beyondblue National Postnatal Depression Program. Participants completed questionnaires at 26-32 weeks gestation and a subsample (N = 161) also completed questionnaires at 10-12 weeks postnatally. Depression levels were measured using the Beck Depression Inventory (BDI). Regression analyses identified significant risk factors for each outcome measure. For antenatal depression, significant predictors included low self-esteem, antenatal anxiety, low social support, negative cognitive style, major life events, low income, and history of abuse. For postnatal depression, antenatal depression, a history of depression, and concurrent parenting stress were significant predictors. Antenatal depression was a mediator between seven risk factors and postnatal depression. For parenting stress, postnatal depression was the only significant predictor and also mediated the relationship between five risk factors. The study highlights the importance of early identification and treatment of perinatal depression to prevent and manage parenting stress.This study investigates the risk factors for antenatal depression, postnatal depression, and parenting stress. The researchers recruited 367 primipara and multipara women from two major hospitals in Melbourne, Australia, as part of the beyondblue National Postnatal Depression Program. Participants completed questionnaires at 26-32 weeks gestation and a subsample (N = 161) also completed questionnaires at 10-12 weeks postnatally. Depression levels were measured using the Beck Depression Inventory (BDI). Regression analyses identified significant risk factors for each outcome measure. For antenatal depression, significant predictors included low self-esteem, antenatal anxiety, low social support, negative cognitive style, major life events, low income, and history of abuse. For postnatal depression, antenatal depression, a history of depression, and concurrent parenting stress were significant predictors. Antenatal depression was a mediator between seven risk factors and postnatal depression. For parenting stress, postnatal depression was the only significant predictor and also mediated the relationship between five risk factors. The study highlights the importance of early identification and treatment of perinatal depression to prevent and manage parenting stress.