My friend is suffering from puerperal psychosis and has been prescribed some drug. Is that all they will do?

Medications. Puerperal psychosis is a psychiatric emergency that often requires inpatient treatment. Symptoms are typically manic or mixed, with restlessness, agitation, sleep disturbance, paranoia, delusions, disorganized thinking, impulsivity, and behaviors that place mother and infant at risk. Antipsychotic and possibly mood-stabilizing medicines are needed; later treatment can include more psychotherapy.
Ideally, we first. Need to get control of the psychotic symptoms and perhaps even get the depression a bit better before she is also referred to a therapist. The best treatment is a combination of medication and therapy.