While no single cause of PPD has been determined, many risk factors have been identified. A 2023 meta-analysis found the following as major risk factors: a personal history of mental illness, childcare stress, the baby’s temperament (e.g., infantile colic, inconsolable crying), stressful life events, inadequate social support, the maternity blues, and conflict or dissatisfaction with one’s partner.[1] Low socioeconomic status, abuse, gestational diabetes, vitamin D deficiency, and pregnancy or delivery complications have also been identified as risk factors for PPD.[2][3] Additionally, a 2013 Canadian study found that women who lived in cities of over 500,000 people were at higher risk of postpartum depression, possibly due to lack of social support.[4] Neuroendocrinological factors, genetic predisposition and family history may also be at play.[5] Exclusive breastfeeding is associated with a lower risk of PPD,[6] although it’s unclear whether this is a cause or effect.