Letters to the Editor
Level of Functioning in Hypomania of Bipolar II Disorder
Dear Editor:
According to the DSM-IV-TR, hypomania in bipolar II disorder (BD II) must not display marked impairment of functioning, compared with mania, and the change in functioning may be increased or decreased without reporting which is more common (1). Because of the marked impairment of functioning criterion, the DSM-IV-TR’s unclear boundary between mania and hypo- mania can lead to misclassification (that is, symptoms are the same, apart from psychosis). If the change in functioning in hypomania were more often increased, the difference between mania and hypomania could be clarified.
This study examines whether the level of functioning in hypomania of BD II was more often increased than decreased. In a private practice, 140 consecutively presenting BD II outpatients were interviewed during remission with the Structured Clinical Interview for DSM-IV-Clinician Version (SCID-CV) (2), as modified by Benazzi and Akiskal (3). Remission was defined as a Global Assessment of Functioning (GAF) scale score of 80 to 90 for at least 1 month (1). In Italy, private practice is first or second (after family doctors) in the line of treatment of mood disorders. Private practice is more representative of the BD II population than national mental health and university services, where most severe disorders are usually seen. Patients with substance-related and borderline personality disorders (BPDs) were excluded to avoid confounding the diagnosis of BD II (4) and because they are very rarely seen in the private practice setting (5). Details about study methods are in previous reports (3,6). Interviewing during remission should have reduced the negative cognitive bias of depression (7), which can lead to underreporting positive events. The SCID-CV question on functioning was supplemented by Angst and colleagues’ detailed questions about increased functioning during hypomania (8). Increased functioning was defined according to the DSM-IV text description: there had to be an observable change in functioning (that is, “superior functioning in a wide range of activities, life’s problems never seem to get out of hand, is sought out by others because of his or her many positive qualities” [1]). The GAF score had to be 100. The level of functioning most common during an individual’s hypomanic episodes was used to rate the subject’s functioning as increased, mildly decreased, or never showing marked impairment.
Results
The patients’ mean (SD) age was 41.8 (11.7) years; 69.3% (n = 97) were women, and 30.7% (n = 43) were men. More than 1 hypomanic episode was present in 84.3% (n = 118). Increased functioning during hypomania was found in 73.6% (n = 103), and mildly decreased functioning was found in 26.4% (n = 37).
These findings suggest that almost 3 out of 4 subjects with BD II, seen in private practice, may have increased functioning during hypomania. Results are in line with classic descriptions of hypomania (9,10), which report that most hypomanic episodes show improved functioning. Kraepelin’s description of hypomania, based on hospital patients (11), postulates that some impairment is more likely. Hecker, who worked in private practice, usually found increased functioning (10). Dunner and colleagues’ first definition of BD II required no hospital treatment for hypomania and no marked impairment (12). Later, Dunner and Tay required no impairment (13), suggesting that hypomania usually has improved functioning.
A limitation of this study is the exclusion of subjects with substance-related disorders and BPD. This subgroup of BD II would be called “dark” by Akiskal and colleagues (14), because the associated cyclothymic temperament usually causes impaired functioning. The present study’s BD II is called “sunny” (14), because features of cyclothymic temperament (which have similarities with BPD and substance-related disorders) are lacking. Patients with “dark” BD II are more common in tertiary care settings, where the most severely ill patients are seen (40% “dark”) (14). In our setting, most patients with BD II were “sunny” (that is, they had increased functioning during hypomania). By focusing on increased functioning during hypomania, false negatives should be reduced (that is, sensitivity should be higher) and the high BD II under- diagnosis (15) should also be reduced— at least in nontertiary care settings. Because subjects with BD II were interviewed during remission, a bias leading to an overestimation of positive aspects of hypomania and an underestimation of possible negative aspects (a common bias during hypomanic episodes) should be significantly reduced.
References
1. American Psychiatric Association. Diagnostic and statistical manual of mental disorders. 4th ed. Text revision. Washington (DC): American Psychiatric Association; 2000.
2. First MB, Spitzer RL, Gibbon M, Williams JBW. Structured Clinical Interview for DSM-IV Axis I Disorders-Clinician Version (SCID-CV). Washington (DC): American Psychiatric Press; 1997.
3. Benazzi F, Akiskal HS. Refining the evaluation of bipolar II: beyond the strict SCID-CV guidelines for hypomania. J Affect Disord 2003;73:33–8.
4. Akiskal HS, Pinto O. The evolving bipolar spectrum: prototypes I, II, III, and IV. In: Akiskal HS, editor. Bipolarity: beyond classic mania. Psychiatr Clin North Am 1999;22:517–34.
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8. Angst J, Gamma A, Benazzi F, Ajdacic V, Eich D, Rossler W. Toward a re-definition of subthreshold bipolarity: epidemiology and proposed criteria for bipolar-II, minor bipolar disorders and hypomania. J Affect Disord 2003;73:133–46.
9. Sedler MJ. Falret’s discovery: the origin of the concept of bipolar affective illness. Am J Psychiatry 1983;140:1127–33.
10. Koukopoulos A. Ewald Hecker’s description of cyclothymia as a cyclical mood disorder: its relevance to the modern concept of bipolar II. J Affect Disord 2003;73:199–5.
11. Kraepelin E. Manic–depressive insanity and paranoia. Edinburgh: E and S Livingstone; 1921.
12. Dunner DL, Gershon ES, Goodwin FK. Heritable factors in the severity of affective illness. Biol Psychiatry 1976;11:31–42.
13. Dunner DL, Tay KL. Diagnostic reliability of the history of hypomania in bipolar II patients and patients with major depression. Compr Psychiatry 1993;34:303–7.
14. Akiskal HS, Hantouche EG, Allilaire JF. Bipolar II with and without cyclothymic temperament: “dark” and “sunny” expressions of soft bipolarity. J Affect Disord 2003;73:49–57.
15. Ghaemi SN, Ko JY, Goodwin FK. “Cade’s disease” and beyond: misdiagnosis, antidepressant use, and a proposed definition for bipolar spectrum disorder. Can J Psychiatry 2002;47:125–34.
Franco Benazzi, MD,
Forli, Italy
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