Challenging DSM-IV criteria for hypomania: diagnosing based on number of no-priority symptoms

DSM-IV definition of hypomania of bipolar-II disorder (BP-II), which includes elevated/irritable mood change as core feature (i.e., it must always be present), is not based on sound evidence.

Following classic descriptions of hypomania, was to test if hypomania could be diagnosed on the basis of its number (9) of DSM-IV symptoms, setting no-priority symptom.

Consecutive 422 depression-remitted outpatients were re-interviewed by a mood specialist psychiatrist using the Structured Clinical Interview for DSM-IV Axis I Disorders-Clinician Version [a semi-structured interview modified by Benazzi and Akiskal (J Affect Disord, 2003; J Clin Psychiatry, 2005) to improve the probing for BP-II] in a private practice. History of episodes of subthreshold (i.e., 2 or more symptoms) and threshold (i.e., meeting DSM-IV criteria of elevated mood plus at least 3 symptoms, or irritable mood plus at least 4) hypomania, lasting at least 2 days, and which were the most common symptoms during the episodes, were systematically assessed.

Bipolar-II disorder (BP-II) patients (according to DSM-IV criteria, apart from hypomania duration) were 260, and major depressive disorder (MDD) patients were 162. Mood change was present in all BP-II by definition. The most common symptoms were overactivity, which was present in almost all BP-II, followed by elevated mood and racing thoughts. ROC analysis of the number of hypomanic symptoms predicting BP-II found that a cut point of 5 or more symptoms over 9 had the best combination of sensitivity (90%) and specificity (84%), and the highest figure of correctly classified (87%) BP-II. History of episodes of 5 or more hypomanic symptoms was met by almost all BP-II.

Single interviewer.

Following classic descriptions of hypomania, not setting any priority among the three basic domains of hypomania (mood, thinking, behavior), results suggest that a cutoff number of 5 symptoms over 9 (of those listed by DSM-IV) could be used to diagnose hypomania of BP-II. Diagnosing hypomania by counting a checklist of symptoms should make it easier to diagnose BP-II, and should reduce the current high misdiagnosis of BP-II as MDD, significantly impacting the treatment of depression.