Many medical conditions common among new mothers can cause depressed mood, fatigue, and other symptoms that suggest postpartum depression. To help you quickly pinpoint the source of a new mother’s depressive symptoms and plan treatment, this article reviews:
- new-onset or pre-existing neurologic, cardiovascular, thyroid, and other conditions that mimic postpartum depression
- risk factors and clinical features that distinguish postpartum depression from other psychiatric disorders
- laboratory tests that confirm or rule out medical problems.
Case: ‘I can’t sleep’
Mrs. A, age 40, sleeps 2 hours nightly at most. Awakened by her 3-month-old daughter’s overnight crying, she lies awake and ruminates over the day’s events. Throughout the day, she fears she cannot care for her baby and 2-year-old son, and she depends on a family member to stay home with her. Financial concerns force her back to work 3 months after giving birth, but she is so despondent that she can barely function.
Mrs. A’s primary care physician diagnoses primary insomnia and prescribes mirtazapine and zolpidem, 15 and 10 mg each night, respectively, but her sleep disturbance persists after 6 weeks. The physician adds the hypnotic temazepam, 15 mg at night, and the sedating anticonvulsant gabapentin, 300 mg at bedtime. Both are titrated over 6 months to 45 mg and 1,800 mg at bedtime, respectively, but Mrs. A continues to lose sleep.
After 6 months, the doctor stops mirtazapine because Mrs. A has gained 20 lb. A switch to sertraline, 25 mg/d, has no effect.
Eighteen months after symptom onset, Mrs. A still sleeps poorly, even though her daughter—now age 2—sleeps through the night. Her depressed mood—undiagnosed by the physician—continues to worsen. She sees a psychiatrist after routine blood tests and a sleep study reveal no medical cause for her insomnia.
Is it postpartum depression?
Mrs. A’s despondent mood, sleep disturbances, feelings of inadequacy as a parent, and impaired concentration suggest postpartum depression. Ego-dystonic obsessive thoughts of harming the infant might emerge, although nonpsychotic patients rarely act upon them.1
Finding risk factors for postpartum depression can clarify the diagnosis. Ask the patient:
- When did you first notice symptoms? DSMIV-TR says postpartum depression usually begins within 4 weeks of giving birth,2 but most researchers define the postpartum period as ≤6 months after delivery.1,3 Mrs. A’s depression and insomnia started 3 months after childbirth.
- Have you been depressed before? Women with past postpartum or other depressive episodes face a high risk of recurrence after subsequent pregnancies.1,3 Active eating disorder during pregnancy4 and past premenstrual dysphoric disorder also are risk factors.1,3
- Has anyone in your family had depression? This increases postpartum depression risk.5
- Who is helping you? Psychosocial stress and lack of social support can fuel postpartum depression.1,3 Mrs. A gets practical help from family members, but life’s pressures are taking their toll.
Is it another mental illness?
Screen women with postpartum depressive symptoms for anxiety, which is highly comorbid with depression.6
Include bipolar disorder in the differential diagnosis. Ask new mothers with depressive symptoms if they feel inexplicably happy, irritable, or unusually energetic at times. Also screen for postpartum psychosis, which can progress to bipolar disorder7 and—worse—greatly increase the risk of infanticide.
The Edinburgh Postnatal Depression Scale,8 a 10-item self-report screening tool that takes about 5 minutes to complete, can help identify postpartum depression (see Related resources).
Case continued: A postpartum headache
During our initial interview, Mrs. A denies thoughts of harming herself or her children, and psychotic symptoms are not apparent. She reports no past depressive or anxiety episodes and does not use alcohol or illicit drugs. Her sister has a history of depression (not postpartum).
During review of systems, Mrs. A complains of persistent headaches. Brain MRI reveals a 4.5×5 mm microadenoma in the pituitary gland. We refer her to an endocrinologist, who obtains prolactin readings of 92 and 122.4 ng/mL (normal range, 2.8 to 29.2 ng/mL).
Discussion. Mrs. A had few predictive factors for postpartum depression, an atypical presentation with insomnia as the main symptom, and incomplete response after 18 months of treatment. These findings—plus her elevated prolactin and brain MRI results—suggest a medical cause.
Is it a medical problem?
Pre-existing or new-onset postpartum medical conditions can confound the diagnosis.
- Fatigue can mimic depression’s neurovegetative signs (poor energy, decreased appetite, sleep). Common causes include sleep deprivation, thyroid disorders, anemia, cardiomyopathy, and infections (Table 1).9
- Weight change could signal a medical condition whose symptoms resemble postpartum depression—such as diabetes or human immunodeficiency virus (HIV) (Table 2).
- Other disorders—including neurologic diseases, prolactinomas, systemic lupus erythematosus, diabetes, and rheumatoid arthritis—can cause depressive and other psychiatric symptoms (Table 3).