Postpartum depression (PPD), also called postnatal depression, is a type of mood disorder associated with childbirth, which can affect both sexes. Symptoms may include extreme sadness, low energy, anxiety, crying episodes, irritability, and changes in sleeping or eating patterns. Onset is typically between one week and one month following childbirth.

Source : Wikipedia

It has been estimated to affect around 15% of women after childbirth.

Like Major Depressive Disorderplugin-autotooltip__plain plugin-autotooltip_bigMajor Depressive Disorder

Major Depressive Disorder (MDD), also known simply as 'depression', is a mental disorder characterized by at least two weeks of pervasive low mood.

Current estimates are that severe depression affects around 2% of the global population at any given time, currently more than 150 million. The majority of cases don't appear to have an obvious personal and/or societal cause., pinpointing the causes of Postpartum Depression (a.k.a. Postnatal Depression) has proved difficult.

Hormonal and physical changes, personal and family history of depression, and the stress of caring for a new baby may be factors. There are suggestions that vitamin B12 deficiency and an underactive thyroid may also sometimes be triggers.

Further info UK Royal College of Psychiatrists