Question 1

What is the difference between MDD and bipolar depression?

Accepted Answer

The depressive episodes can look identical in cross-section — both present with sadness, anhedonia, sleep disturbance, fatigue, and concentration difficulty. The diagnostic difference is whether the patient has ever had a manic or hypomanic episode. If there is a lifetime history of mania (bipolar I) or hypomania (bipolar II), all depressive episodes are classified under bipolar disorder, not MDD. The distinction matters because treatment diverges sharply — antidepressant monotherapy is first-line for MDD but carries risks in bipolar depression.

Question 2

Can an antidepressant cause mania?

Accepted Answer

Yes. Antidepressant-induced manic switch is a recognized risk in patients with bipolar disorder. Per DSM-5-TR, a full manic or hypomanic episode that emerges during antidepressant treatment and persists at syndromal level beyond the expected physiological effect of the substance counts toward a bipolar diagnosis. This is a commonly tested board point. SNRIs and TCAs may carry higher switch risk than SSRIs, though estimates vary by study.

Question 3

What medications are used for bipolar depression?

Accepted Answer

Quetiapine and lurasidone have the strongest evidence and FDA approval for acute bipolar depression. Lamotrigine is primarily used for maintenance and depressive episode prevention rather than acute treatment. Lithium may be part of the treatment foundation. If an antidepressant is considered, it is typically used in combination with a mood stabilizer rather than as monotherapy. This contrasts with MDD, where SSRI or SNRI monotherapy is first-line.

Question 4

How do you screen for bipolar disorder in a depressed patient?

Accepted Answer

The most useful screening approach is a direct question about lifetime mood elevation: 'Has there ever been a period of several days or more when you felt unusually energetic, needed much less sleep than normal, felt on top of the world, or did things that were out of character?' Patients often do not report hypomanic episodes spontaneously because they experience them as positive. Collateral sources — partners, family members — are often more aware of hypomanic behavior than the patient. Validated tools like the MDQ or HCL-32 can supplement the clinical interview.

Question 5

A 22-year-old college student presents with a 3-week history of depressed mood, hypersomnia (sleeping 14 hours/day), increased appetite with 10-pound weight gain, difficulty concentrating, and suicidal ideation. She reports a period 6 months ago when she felt "amazing" for about 5 days — she slept only 3 hours per night, started multiple creative projects, talked rapidly, and spent $3,000 on art supplies she did not need. She says that period "didn't feel like a problem." Her mother has bipolar I disorder. Which pharmacotherapy class is most appropriate for this patient's current depressive episode?

Accepted Answer

This patient has bipolar II disorder, current episode depressed. The key evidence is her 5-day history of decreased need for sleep with preserved energy, increased productivity, rapid speech, and impulsive spending — this is consistent with hypomanic symptoms lasting at least 4 days (decreased need for sleep with increased activation and goal-directed activity), especially given family history and the episodic pattern described. She also has a first-degree family history of bipolar I disorder and atypical depressive features (hypersomnia, hyperphagia). An atypical antipsychotic with FDA approval for bipolar depression (B) — such as quetiapine or lurasidone — is appropriate because this is a bipolar depressive episode, not unipolar MDD. SSRI monotherapy (A), SNRI monotherapy (C), and NDRI monotherapy (D) are all antidepressant monotherapy, which carries risk of manic switch in bipolar depression. Among common antidepressants, SNRIs may carry a higher switch risk than SSRIs, though estimates vary by study.

Question 6

A 35-year-old man with a 4-year history of diagnosed major depressive disorder presents for follow-up. He has not responded to adequate trials of sertraline, escitalopram, and bupropion. During the visit, his wife mentions that "every few months he has these weeks where he barely sleeps, talks nonstop, and makes impulsive decisions — he bought a boat last summer that we can't afford." The patient says those periods are "just my good weeks." What is the most important next step in management?

Accepted Answer

This is a presentation of misdiagnosed bipolar disorder presenting as treatment-resistant MDD. The wife's collateral history reveals episodic symptoms concerning for bipolar spectrum illness — decreased need for sleep, talking nonstop, and impulsive spending occurring in discrete episodes. The patient minimizes these episodes as "good weeks," which is characteristic because hypomania and mania are often ego-syntonic. Three failed antidepressant trials should prompt diagnostic reconsideration. The most important step is to reassess the diagnosis (C) and transition to appropriate treatment. Aripiprazole augmentation (A) is used for MDD augmentation but does not address the diagnostic question. Switching to a TCA (B) would be concerning — TCAs carry elevated risk of manic switch in bipolar disorder. Lithium augmentation (D) could provide some benefit given lithium's mood-stabilizing properties, but it does not address the fundamental diagnostic reassessment that is needed, and the question asks for the most important next step.

Question 7

A 29-year-old woman with a history of major depressive disorder was started on fluoxetine 20 mg daily 3 weeks ago. She presents today with elevated mood, decreased need for sleep (sleeping 3 hours/night and feeling "great"), pressured speech, and grandiose plans to start a multinational company. These symptoms began 5 days ago and are persisting. She has no history of substance use. According to DSM-5-TR, which of the following is the most accurate diagnostic consideration?

Accepted Answer

Per DSM-5-TR, a full manic or hypomanic episode that emerges during antidepressant treatment and persists at syndromal level beyond what would be expected from a transient medication effect counts toward a bipolar diagnosis. This presentation is consistent with a manic syndrome (elevated mood, decreased need for sleep, grandiosity, pressured speech) that has persisted at syndromal level. This presentation should prompt diagnostic reconsideration as bipolar I disorder (C). Dismissing this as merely a medication side effect (A) is inconsistent with DSM-5-TR criteria when symptoms persist at syndromal level. Classifying it as only substance-induced (B) is less consistent if symptoms persist at full syndromal level beyond expected physiological effects. Mixed features specifier (D) would be less fitting if the episode meets full manic criteria rather than representing subthreshold manic symptoms during depression.

MDD vs Bipolar Depression

Frequently Asked Questions

What is the difference between MDD and bipolar depression?

Can an antidepressant cause mania?

What medications are used for bipolar depression?

How do you screen for bipolar disorder in a depressed patient?

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