Pseudounipolar Depression

Question:

"I have recently heard a lecture about "pseudounipolar" depression. Does this form of mood disorder really exist?"

Vladimir Maletic, MD:
Unfortunately, there is a lack of consensus about the existence of "pseudounipolar" depression. Many patients who are diagnosed as depressive disorder NOS or treatment-resistant depression, display a combination of depressive symptomatology combined with two or more hypomanic/manic symptoms, yet they do not meet syndromal criteria for any other mood state. Most frequently patients will complain of depression, social anxiety, obsessive tendencies, irritability, emotional liability, "crowded mind," and difficulty falling asleep because their mind "will just not turn off."

Our diagnostic taxonomy offers little help; unipolar and bipolar depression have the same criteria. Therefore, one must rely on information about mania or hypomania to make the distinction. Patients will seldom spontaneously report hypomanic symptoms; sometimes it is due to lack of awareness, at other times it is reluctance to discuss embarrassing behaviors from the past.

Using a structured interview, Cassano and colleagues ¹  discovered frequent presence of hypomanic symptoms in context of unipolar depression. Hypomanic symptoms were not normally distributed, about one-third of the patients with depression accounted for most of the hypomanic/manic symptoms. These patients were, for the research purposes, labeled as "pseudounipolar." ²  Described depressive variant is characterized by presence of a few hypomanic symptoms and more pronounced social anxiety, panic attacks, and obsessive tendencies relative to other patients suffering from depression. ²  Proper recognition of "pseudounipolar" depression may be of significant clinical relevance since these patients are less likely to respond to conventional antidepressant treatments and more likely to have psychotic features. ³  They will often benefit from adjunct mood-stabilizing agents.

–Vladimir Maletic, MD

References

1. Cassano GB, Rucci P, Frank E, et al . The mood spectrum in unipolar and bipolar disorder: arguments for a unitary approach.  Am J Psychiatry . 2004;161(7):1264-1269.
2. Cassano GB . Threshold and subthreshold mania in mood and anxiety disorders. Sixth International Conference on Bipolar Disorder; June 16-18, 2005; Pittsburgh, PA.
3. Smith DJ, Forty L, Russell E, et al . Sub-threshold manic symptoms in recurrent major depressive disorder are a marker for poor outcome.  Acta Psychiatr Scand . 2009;119(4):325-329.