A patient presents with a single 10-day episode of elevated mood, grandiosity, decreased sleep need, and pressured speech severe enough to require hospitalization. She has never had a depressive episode. What is the correct DSM-5 diagnosis?
ACannot diagnose Bipolar I because no depressive episode has occurred
BBipolar II Disorder, since only one pole of the disorder is present
CBipolar I Disorder, since a single full manic episode satisfies the diagnostic criteria
DCyclothymic Disorder, as the episode lacks sufficient duration for Bipolar I
Bipolar I Disorder requires only a full manic episode — major depressive episodes are common but not required. A manic episode lasting at least 7 days (or any duration if hospitalization is required) with the characteristic symptom cluster qualifies. The most common misconception is that Bipolar I requires 'both poles.' Bipolar II, by contrast, requires at least one hypomanic episode AND at least one major depressive episode.
Question 2 Multiple Choice
A patient with recurrent major depression is being considered for antidepressant therapy. Which finding in their history would most importantly change this treatment decision?
AA family history of anxiety disorders
BA prior episode meeting full criteria for mania, suggesting Bipolar I
CA history of panic attacks during depressive episodes
DConcurrent hypothyroidism
Antidepressant monotherapy in a patient with Bipolar I carries a significant risk of triggering mania ('manic switching'). The treatment of bipolar depression differs critically from unipolar depression: mood stabilizers are first-line, and antidepressants are used only cautiously in combination. A prior manic episode is the most clinically critical finding that redirects treatment — misdiagnosis of Bipolar I as unipolar depression is a major source of harm in psychiatric practice.
Question 3 True / False
A Bipolar I diagnosis requires the patient to have experienced at least one major depressive episode in addition to a manic episode.
TTrue
FFalse
Answer: False
This is a common and clinically important misconception. Bipolar I requires only a full manic episode — depressive episodes are common and add to burden of illness, but they are not required by DSM-5 criteria. It is Bipolar II that explicitly requires both hypomanic and major depressive episodes. Confusing the two can lead to missed diagnoses in patients who present first with mania.
Question 4 True / False
The grandiosity and risky behavior in mania reflect pathological hyperactivation of dopaminergic reward circuits, not simply extreme happiness.
TTrue
FFalse
Answer: True
Mania involves dysregulation of the mesolimbic dopamine pathway — the system underlying goal-directed motivation and reward anticipation. The result is a pathologically inflated sense of goal importance, compressed risk perception, and reduced fatigue. Manic patients engage in catastrophically unwise behaviors because their reward system signals that goals are supremely important and risks are trivially small. This neurobiological framing distinguishes mania from normal happiness and explains the severe impairment.
Question 5 Short Answer
Why is treating bipolar depression with antidepressant monotherapy potentially harmful in a way that does not apply to treating unipolar depression?
Think about your answer, then reveal below.
Model answer: In Bipolar I, the mood regulatory system is dysregulated in both directions — antidepressants can push the mood state from depression into mania ('manic switching'). This risk is absent in unipolar depression because there is no manic pole to trigger. Mood stabilizers that work across both poles are appropriate first-line treatment for bipolar depression; antidepressants are used only cautiously and typically in combination with mood stabilizers.
The key insight is that bipolar disorder is not 'depression plus mania as separate problems' — the regulatory system itself is dysregulated bidirectionally. Treating only the depressive pole with antidepressants can destabilize the system toward the manic pole. This makes careful longitudinal history-taking essential before prescribing antidepressants to any patient presenting with depression.