Differential Diagnosis of Postpartum Psychosis

New mothers may present to the emergency department (ED) with symptoms ranging from mild anxiety to severe psychosis. Postpartum psychosis has abrupt onset and severe symptoms and usually occurs in the immediate postpartum period. Patients who have had a previous episode of postpartum psychosis or have first-degree relatives with postpartum psychosis or bipolar disorder are at higher risk.

ED Presentation

Mrs D, a 26-year-old married mother of a 7-day-old full-term boy, is brought to the ED by her husband because of his concerns about her increasingly anxious behavior and insomnia over the past 3 days. On initial examination, the obstetric resident finds a young, healthy-appearing woman pacing around the examining room demanding to be released. She states, "I need to get home to clean the baby's room!" The resident does not know this patient and is annoyed at being bothered with what appear to be overanxious new parents.

The resident briefly reviews the patient's vital signs and finds her to be afebrile but tachycardic and mildly hypertensive. The patient denies any physical complaints except for "my head is hurting so that I can't sleep." A physical examination reveals no abnormalities except for a mildly enlarged thyroid. The resident orders a complete blood cell count, blood chemistry panel, toxicology screen, and thyroid function tests. The resident becomes concerned about thyroid toxicosis or drug intoxication, such as from cocaine, because of the patient's vital signs and new onset of agitated behavior.

When findings on the physical examination are normal and laboratory test results are within normal limits, the obstetric resident begins to take a more extensive medical and psychiatric history. She discovers that the patient has no significant medical or psychiatric history. The patient and her husband deny that she uses drugs or smokes tobacco. She has a remote history of excessive alcohol use as a teenager. Two days ago, she began drinking red wine at night to help her sleep. Before pregnancy, the patient drank 1 to 2 cups of caffeinated coffee per day. She discontinued caffeine intake during her pregnancy and has not resumed consumption of caffeine.

The obstetric resident becomes increasingly concerned about a psychiatric issue when the patient's husband states that the patient's behavior is completely out of character for her and that the behavior has become increasingly worse and erratic. He fears for his wife and his baby's safety when he is not with them. The obstetric resident calls for a psychiatric consultation.

Psychiatric Consultation

The psychiatric resident learns that the patient gave birth 1 week ago to her first child. The labor was more than 24 hours, but there were no complications and the infant was healthy. Both parents and extended family were ecstatic after the boy's birth. The first few days were uneventful, but on day 3, Mrs D began to be increasingly short-tempered with her husband, becoming irate and taking the baby away when he did not follow her explicit instructions on how to bathe, feed, and change the baby. She was argumentative with family members and would not allow anyone but herself to care for the infant. Within an hour of arguing with her family, she would return to being happy again, as if the argument had never happened. The husband reports that his wife has not slept in the past 3 days because she has been up at night doing laundry and cleaning constantly. He finds it difficult to maintain a conversation with her because she is very easily distracted.

Mrs D claims that her husband is overreacting. She does not find her insomnia to be a problem. In fact, she thinks it is a good thing, because she has so many household chores to do and thank-you notes to write. She is annoyed and irritated with everyone, because she thinks she is the only one who can care for her son adequately. On examination, Mrs D denies any auditory or visual hallucinations and adamantly denies any thoughts of harming herself or her infant ("Why would I do that? He is an angel from God!"). Mrs D denies feeling sad or depressed but does admit to being irritable and angry with her husband. She thinks, however, that her anger is justified, because "he just doesn't know how to care for the baby."

Mrs D does admit to feeling as if her head hurts and is "heavy" but attributes this to having just given birth and not sleeping very well. She is calm throughout the interview and engages readily in conversation. However, the nurses observe that when Mrs D is not being interviewed, she is pacing, constantly touching the baby, and arguing with her husband. The resident is not sure whether the symptoms are consistent with normal adaptation to a new baby, whether the husband is overreacting, or whether this is a patient who is experiencing a significant postpartum psychiatric episode that requires management.

Further Diagnostic Considerations

On review of the case, the attending physician asks the resident the following questions to determine risk factors for postpartum psychosis or postpartum depression:

•Does the patient have any history of mood instability--either depressive episodes or hypomania¹--even if they do not meet Diagnostic and Statistical Manual of Mental Disorders IV criteria for major depression or mania? Many women who experience postpartum psychosis or a postpartum affective episode have an undiagnosed history of labile moods that may not reach the level of clinical significance requiring intervention. Therefore, the interview must go beyond a history of psychiatric hospitalizations or formal treatment.

•Is there any family history of psychiatric illness--in particular, bipolar disorder or postpartum depression or psychosis--among the mother's immediate relatives? Family studies show a much greater risk of postpartum psychosis among women whose immediate female relatives (mothers, sisters) also had a postpartum psychotic episode.²

•Did the patient have any symptoms of depression, anxiety, or obsessive-compulsive disorder (OCD) before or during pregnancy? Depression during pregnancy is one of the strongest risk factors for postpartum depression.³ Women with OCD may have an exacerbation of their disorder in the postpartum period. Often, obsessive cleaning can be a symptom of OCD, but it must be differentiated from psychosis. Therefore, understanding the cause of the cleaning is critical.

•Did the patient have any mood symptoms following previous pregnancies, miscarriages, or terminations or during her menstrual cycle? Women who have a history of depression following reproductive events or who have a history of premenstrual dysphoric disorder are at increased risk for postpartum depression.

• Did you explore paranoia, ideas of reference, the possible grandiose symptoms of being the only one able to care for the infant, delusions surrounding the child, and more subtle thoughts of harming the child? Women with postpartum psychosis may have delusions that are religious in nature and/or grandiose. The delusions often focus on the infant, and women may harm their infants in an effort to save their "pure angel" from the devil or from other perceived threats. Without extensive questioning, these delusions can be missed, with tragic consequences.

On reinterviewing the patient and her husband in more detail, the psychiatric resident elicits that the patient thinks that her child is truly an angel from God and may need to return to God if the house cannot be cleaned adequately. She is constantly cleaning her home to protect her child. The resident also discovers that the patient's mother was hospitalized for a nervous breakdown following the birth of her second child, but the patient does not know what form of treatment her mother received or the diagnosis. Finally, her husband reinforces his concerns for his child and for her because he repeatedly states that her actions are out of character. He does report that during their college days, she often pulled "all-nighters" for days on end and then crashed into sleep for a few days but that she never had a full-blown manic episode.

Diagnosis and Disposition

With the new information, a working diagnosis of brief psychotic disorder with postpartum onset is made with a differential that includes a high likelihood of bipolar disorder. The patient is hospitalized in the inpatient psychiatric unit. Because of the severity of her symptoms, the unpredictability of her acting on her delusions, and the potential harm to her child and herself, she is not a candidate for partial hospitalization or outpatient therapy at this time. She requires inpatient hospitalization with immediate medication stabilization.

After results of laboratory tests and an ECG examination are known, an atypical antipsychotic agent and lithium are started. The choice of medication follows the need to address the immediate psychotic symptoms as well as the high probability that Mrs D has an evolving bipolar disorder.^4,5

Discussion

Postpartum psychosis is the most severe and uncommon form of postnatal affective illness, with rates of 1 to 2 episodes per 1000 deliveries.⁶ The clinical onset is rapid, with symptoms occurring as early as the first 48 to 72 hours postpartum, although the majority of episodes develop within the first 2 weeks after delivery.

Bipolar episodes in the puerperium are often rapid in onset, are of a mixed affective type, show an atypical and amorphous psychotic symptomatology with a variability in clinical presentation from hour to hour (kaleidoscopic), and can rapidly escalate in severity.^7,8 For this reason, it is imperative to observe the woman over a sustained period and to rely on key informants' accounts of her behavior.

Risk factors. For some women, the postpartum psychotic episode will also be their first psychiatric episode; however, research has consistently shown that women in whom bipolar disorder is diagnosed are at very high risk for postpartum psychosis, with 25% to 50% of deliveries affected.^2,8

This high rate of illness represents a many hundred-fold increase from the base rate of 1 in 1000 deliveries. In addition to a history of bipolar disorder, other important risk factors include having experienced a previous episode of postpartum psychosis, having a first-degree relative with postpartum psychosis, and having a first-degree relative with bipolar disorder.²

Risk of suicide/infanticide.Although rare, suicide and infanticide are tragic consequences of postpartum psychosis. Because of the nature of psychotic or depressive symptoms, new mothers are at risk for injuring their children through practical incompetence or delusions.⁹

The results of a confidential inquiry in the United Kingdom into maternal deaths have shown that sui-cide is the leading cause of mater- nal mortality in the United Kingdom, accounting for 28% of maternal deaths.¹⁰ The majority of women who died by suicide suffered from postpartum psychosis.

Infanticide is rare, occurring in 1 to 3 of 50,000 births^11,12; however, mothers with postpartum psychotic disorders commit a significant percentage of these murders, and estimates suggest that 62% of mothers who commit infanticide go on to commit suicide.¹³ Because of these serious consequences, early diagnosis and management of postnatal illnesses are imperative for the health and well-being of the mother and child.⁹

Outcome. Research suggests that most cases of postpartum psychosis represent a variant of bipolar disorder. Most cases of postpartum psychosis present as mania,^6,14 and long-term follow-up studies have shown that the initial diagnoses of puerperal episodes remain, with most of the diagnoses being bipolar disorder.^15,16 This subsequent diagnostic consistency between episode and lifetime condition points to strong continuities with nonpuerperal psychiatric disorder.¹⁶

Differential diagnosis. Postpartum depression refers to cases of nonpsychotic depression. Episodes of depression with psychotic features in the postnatal period are characterized as postpartum psychosis. Research evidence indicates that psychosocial factors are associated with increased risk of postpartum depression.¹⁷ This is not so for postpartum psychosis.¹⁸ The clinical presentation of postpartum psychosis is severe, abrupt, and almost immediately follows childbirth, in contrast to postpartum depression, which can be abrupt in onset but often has a more gradual onset over the weeks to months following childbirth. Anxiety disorders, including severe OCD, must also be considered in the differential, but usually a history of OCD or obsessive-compulsive tendencies can be elicited ("always a neat freak"), and there is no delusional component.

Treatment. The treatment for postpartum psychosis most often includes immediate hospitalization to ensure the safety of both mother and child. Because of the relationship between bipolar disorder and postpartum psychosis, an initial approach to medication management includes a mood stabilizer and an antipsychotic agent. With the recent addition of atypical antipsychotic medications that are indicated for both psychosis and mania, this may be an alternative; however, no data exist to support a particular medication or combination of medications for management of postpartum psychosis.

Electroconvulsive therapy may be an effective alternative in severe cases. If the primary presentation is a depression with psychotic features, an antidepressant and antipsychotic medication should be considered. However, caution must be used because of the possibility that bipolar disorder may be exacerbated by antidepressant treatment. In addition, mothers and families often require psychotherapy and support following hospitalization to understand and process this difficult and often traumatic experience. *

Research suggests that most cases of postpartum psychosis represent a variant of bipolar disorder.

References:

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