There is  terrific article, "Postpartum Depression: A Debilitating Yet
Often Unassessed Problem" Health of Social Work-- 15(4). 1990 249-328.
It states PPD Postpartum depression affects up to 20% of new mothers.
SOME symptoms of psychosis include:  Mother's refusal to eat, inability
to stop activity, frantic, excessive energy, extreme confusion, loss of
memory, incoherence, bizarre hallucination (walls moving, pets
talking...) suspiciousness, irrational statements, preoccupation with
trivia.

Symptoms of PPD may include:
headaches, numbness, tingline in limbs, chest pains, despondency or
despair, feelings of inadequacy, inability to cope, hopelessness, sense
of powerlessness, excessive concern over baby's health, impaired
concentration, loss of normal interests, loss of interest in sex,
thoughts of suicide, bizarre or strange thoughts of fantasies, feelings
of shame, embarrassment or guilt, extreme or unusual behavior, panic
attacks, anxiety, hostile, new fears or phobias, lack of desire to be
with people, hallucinations, nightmares, extreme guilt, no feelings for
the baby, over concern for the baby, anger toward the baby, feelings of
being out of control, feelings of "going crazy."

I think that all mothers can exhibit some of the above characteristics
and be completely fine, while others will not outwardly exhibit many and
trouble is already brewing.  I don't want these to be taken out of
context. Please see the entire article for some great information.

Many social factors also figure into the picture.  Lack of support,
socioeconomic factors, stress . . .

There is no conclusive evidence on the cause of PPD, but the four
theories are 1) organic 2) psycho dynamic 3) cognitive, and 4)
situational.

I repeat, please do not take these out of context.  IMHO, if you suspect
there is a problem, TALK to the mother, OBSERVE her interaction with
baby and then TALK to her again.

What a tragedy.  There are MANY factors involved.  The once listed above
are just the tip of the iceberg....

Heidi S. Roibal BS, LLLL, IBLCE
Child Development Specialist
New Mexico