Diagnosing MDD and Bipolar Disorder

Norman Sussman, MD, DFAPA

Editor, Primary Psychiatry and Psychiatry Weekly, Professor of Psychiatry, New York University School of Medicine

It is now believed that, even in the absence of any manic or hypomanic episodes, patients may carry a diagnosis of bipolar disorder. It is possible that the term bipolar will disappear and be replaced with such terms are “Mood Spectrum Disorders” or “Recurrent” vs. “Non-Recurrent” mood disorders. The presence of what we currently describe as an elevation of mood may be relegated to a qualifier rather than a definer of the disorder.

Recognizing bipolarity is easy when there have been clear episodes of hypomania or mania. The problem is that many clinicians fail to ask about highs, relying merely on the complaint of depression to make a diagnosis.

It is well established that patients typically seek help only when they are depressed. A consequence of this failure to ask the right diagnostic questions and of underreporting of highs by patients is that we are over diagnosing MDD and under diagnosing BPD.

What should clinicians look for? The following may be helpful:

1. Episode Characteristics and Course of Illness — Episodes of elevated mood, personality and behavioral changes, or irritability followed by a return to baseline or a depressive episode.
2. Age of Onset of First Mood Symptoms — Among those with prepubertal-onset dysthymia and MDD, 20%–40% may become manic or hypomanic when treated with antidepressants and eventually have a bipolar disorder diagnosis.
3. Response to Medications — Good response to mood stabilizers or induction of mania or cycling while on an antidepressant, or lack of response to multiple trials of antidepressants, what many define as treatment-resistant depression, should prompt reconsideration of a unipolar diagnosis.
4. Family History — First degree relatives with clear bipolar symptoms or drug or alcohol abuse argue against a diagnosis of major depression.

Even without the publication of any revised official diagnostic criteria, clinicians should start to inquire about a wider range of dimensions of mood disorders than has been the case, and should reconsider reflexive prescription of antidepressants.

Based on the subtypes, some patients would be treated with antidepressants, and others with mood stabilizers. In any event, in a break with decades of practice, clinicians should start considering bipolarity as the default diagnosis, and MDD as the condition to treat only after bipolar has been ruled out.

Dr. Gary S. Sachs, head of the Bipolar Clinic and Research Program Massachusetts General Hospital, in Boston, and Harvard Medical School, has published papers describing improving treatment for bipolar disorder. For additional information, read: Sachs GS. Strategies for improving treatment of bipolar disorder: integration of measurement and management. Acta Psychiatr Scand Suppl . 2004;(422):7-17.