PP is considered an emergency that necessitates an urgent evaluation, psychiatric referral, and possible hospitalization.54
The initial evaluation requires a thorough history, physical examination, and laboratory investigations to exclude an organic cause for acute psychosis (). Important tests include a complete blood count (CBC), electrolytes, blood urea nitrogen (BUN), creatinine, glucose, vitamin B12
, folate, thyroid function tests, calcium, urinalysis and urine culture in the patient with fever, and a urine drug screen. A careful neurological assessment is essential; this includes a head CT or MRI scan to rule out the presence of a stroke related to ischemia (vascular occlusion) or hemorrhage (uncontrolled hypertension, ruptured arteriovenous malformation, or aneurysm).55
The stroke patient is differentiated from the patient with PP by a history of hypertension or preeclampsia, evidence of fluid/electrolyte imbalance, and complaints of severe headache, unilateral weakness, sensory deficits, and even seizures with the neurological event.56
Summary of Differential Diagnosis and Evaluation of PP
The primary psychiatric diagnosis to consider with the case of early-onset PP is bipolar disorder. Wisner et al.16
found that 95% of PP cases fulfilled Research Diagnostic Criteria (RDC) for cyclic mood disorders at 5-year follow-up. Of these cases, 50% were misdiagnosed at first presentation. Other studies replicated this finding and indicated a high likelihood of a primary cyclic mood illness (43%–66%).3,8,21,57
This is not surprising, as PP and bipolar psychosis or mixed episodes share common symptoms of elation, dysphoria, mood lability, confusion, and heightened sensitivity to sleep deprivation.4,6,8,11,20,31,58–61
Women with a past or family history of bipolar illness are more likely to have BD that precipitates an episode of PP. These patients require antimanic drug treatment. Choices include lithium, such antiepileptic drugs as valproate or carbamazepine, and atypical antipsychotic medication, such as olanzapine, quetiapine, ziprasidone and the newer agent, aripiprazole.
Patients with PP are differentiated from those with unipolar major depression by the presence of cognitive disturbance, delusional beliefs, and disorganized behavior. However, women with a past history of unipolar psychotic depression can relapse shortly after delivery with an episode of PP.4,30,31,62
These patients often report low mood, distraught feelings about their inability to enjoy their new baby, psychomotor slowing or pacing behaviors, anxiety, fatigue, poor concentration, and preoccupations with strange ideas and suspicions.63–65
Without intervention, they are at risk for worsening symptoms, treatment resistance, and mortality.63,65,66
These patients respond best to a combination of antidepressant and antipsychotic drug treatment or electroconvulsive therapy.
PP must be distinguished from obsessive-compulsive (OC) symptoms and obsessive-compulsive disorder (OCD). OC symptoms and OCD are characterized by intrusive thoughts and compulsive, irresistible behaviors. Intrusive thoughts often center on themes of contamination, causing harm to their children, offensive violent or sexual images, religious preoccupations, and urges for symmetry.67
The compulsions include urges to clean, check, repeat, order, and hoard and such mental rituals as counting. Women with postpartum depression commonly experience comorbid OC cognitions (41%–57%).67–69
OC or OCD is differentiated from PP by the preservation of rational judgment and reality testing; patients typically do not act on their aggressive thoughts. Rather, they avoid objects or places that provoke anxiety and suffer discomfort from their unwanted cognitions. This contrasts with patients with florid psychosis, who are unable to discern reality, feel compelled to act on their delusional beliefs, and cannot assess the consequences of their actions.70
First-line treatment for OCD includes serotonin reuptake inhibitors (SRIs), with such agents as sertraline, fluoxetine, and fluvoxamine; the gold-standard drug is clomipramine (which is both an SRI and a nor-epinephrine inhibitor). Most patients require pharmacotherapy in combination with cognitive behavioral therapy. Patients with refractory illness may require augmentation with an atypical antipsychotic drug.
PP could be a presentation of a primary psychotic disorder, such as schizophrenia. Although women with known schizophrenia have a 25% risk for puerperal exacerbations,46,71
many studies have indicated a low prevalence of schizophrenia in early-onset PP (3.4%–4.5%).1
These patients respond best to pharmacotherapy with atypical antipsychotic drugs; if the physician suspects the presence of comorbid depression, the addition of an antidepressant medication is highly recommended. Mothers with schizophrenia also may suffer cognitive impairment. These women could benefit greatly by referral to in-home services for additional support and enhancement of parenting skills.