Post partum. While post partum psychosis is uncommon, post partum depression is. Getting the "blues" following delivery is even more common, but if this becomes worse and more severe, a woman may develop a depressive disorder requiring treatment with an antidepressant medication. This is very important to know, as severe cases of post partum depression can interfere with the attachment and bonding process.
No. It occurs once or twice every 1, 000 childbirths. When it does occur it's often part of a mood disorder, especially bipolar disorder. Medical complications around the pregnancy and first time childbirths are associated with the psychosis about half the time. Tragic though it is, women who suffer the psychosis rarely act on the infanticide and suicide feelings that can be part of the psychosis.