Postpartum period
During the subacute postpartum period, psychological disorders may emerge. Among these are postpartum depression, posttraumatic stress disorder, and in rare cases, puerperal psychosis. Postpartum mental illness can affect both mothers and fathers, and is not uncommon. Early detection and adequate treatment is required. Approximately 25% – 85% of postpartum women will experience the "blues" for a few days. Between 7% and 17% may experience clinical depression, with a higher risk among those women with a history of clinical depression. Prevalence of PTSD following normal childbirth (excluding stillbirth or major complications) is estimated to be between 2.8 and 5.6% at 6 weeks postpartum.
Evolutionary approaches to postpartum depression
One study found that the stress hormone placental corticotropin-releasing hormone (pCRH) mediated the relationship between prenatal family support and fewer depression symptoms postpartum. Studies have also shown that infant health issues represent a suite of risk factors for maternal depression, including preterm birth, low birthweight, birth complications, and infant illness. Another review have found additional risk factors including marital status, relationship quality, infant temperament, and self-esteem.