Evidence-Based Reviews

Soft bipolarity: How to recognize and treat bipolar II disorder

Current Psychiatry. 2009 July;8(7):41-48

Daniel J. Smith, MD, MRCPsych

More realistic criteria for hypomania point to bipolarity in apparently unipolar depression

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References

1. Pies R. The “softer” end of the bipolar spectrum. J Psychiatr Pract. 2002;8(4):189-195.

2. Angst J. The bipolar spectrum. Br J Psychiatry. 2007;190(3):189-191.

3. Smith DJ, Ghaemi SN, Craddock N. The broad clinical spectrum of bipolar disorder: implications for research and practice. J Psychopharmacol. 2008;22(4):397-400.

4. Angst J, Gamma A, Bennazzi F, et al. Toward a re-definition of subthreshold bipolarity: epidemiology and proposed criteria for bipolar-II, minor bipolar disorders and hypomania. J Affect Disord. 2003;73:133-146.

5. Judd LJ, Akiskal HS. The prevalence and disability of bipolar spectrum disorders in the US population: re-analysis of the ECA database taking into account subthreshold cases. J Affect Disord. 2003;73:123-131.

6. Goldberg JF, Harrow M, Whiteside JE. Risk for bipolar illness in patients initially hospitalized for unipolar depression. Am J Psychiatry. 2001;58:1265-1270.

7. Smith DJ, Harrison N, Muir W, et al. The high prevalence of bipolar spectrum disorders in young adults with recurrent depression: toward an innovative diagnostic framework. J Affect Disord. 2005;84(2-3):167-178.

8. Sharma V, Khan M, Smith A. A closer look at treatment resistant depression: is it due to a bipolar diathesis? J Affect Disord. 2005;84(2-3):251-257.

9. Akiskal HS, Benazzi F, Perugi G. Agitated “unipolar” depression re-conceptualized as a depressive mixed state: implications for the antidepressant-suicide controversy. J Affect Disord. 2005;85(3):245-258.

10. Ghaemi SN, Wingo AP, Filkowski MA, et al. Long-term antidepressant treatment in bipolar disorder: meta-analyses of benefits and risks. Acta Psychiatr Scand. 2008;118(5):347-356.

11. National Institute of Health and Clinical Excellence. Bipolar disorder: the management of bipolar disorder in adults, children and adolescents, in primary and secondary care. Issued July 2006. Available at: http://www.nice.org.uk/CG038. Accessed June 3, 2009.

12. American Psychiatric Association practice guidelines. Treatment of patients with bipolar disorder, 2nd ed. Issued April 2002. Available at: http://www.psychiatryonline.com/pracGuide/pracGuideTopic_8.aspx. Accessed June 3, 2009.

13. Judd LL, Akiskal HS, Schletter PJ, et al. A prospective investigation of the natural history of the long-term weekly symptomatic status of bipolar II disorder. Arch Gen Psychiatry. 2003;60:261-269.

14. Forty L, Smith D, Jones L, et al. Clinical differences between bipolar and unipolar depression. Br J Psychiatry. 2008;192(5):388-389.

15. Mitchell PB, Wilhelm K, Parker G, et al. The clinical features of bipolar depression: a comparison with matched major depressive disorder patients. J Clin Psychiatry. 2001;62:212-216.

16. Akiskal HS, Benazzi F. Family history validation of the bipolar nature of depressive mixed states. J Affect Disord. 2003;73(1-2):113-122.

17. Hirschfeld RMA, Williams JB, Spitzer RL, et al. Development and validation of a screening instrument for bipolar spectrum disorder: The Mood Disorder Questionnaire. Am J Psychiatry. 2000;157:1873-1875.

18. Angst J, Adolfsson R, Benazzi F, et al. The HCL-32: towards a self-assessment tool for hypomanic symptoms in outpatients. J Affect Disord. 2005;88(2):217-233.

19. Ghaemi SN, Millar C, Berv DA, et al. Sensitivity and specificity of a new bipolar spectrum diagnostic scale. J Affect Disord. 2005;84:273-277.

20. Allen R, Smith DJ. Screening for bipolar disorder: strengths and limitations of currently available instruments. Primary Care and Community Psychiatry. 2008;13(2):47-51.

21. Goodwin FK, Jamison KR. Manic-depressive illness: bipolar disorders and recurrent depression. 2nd ed. New York, NY: Oxford University Press; 2007.

22. Young AH, Hammond JM. Lithium in mood disorders: increasing evidence base, declining use? Br J Psychiatry. 2007;191(6):474-476.

23. Smith LA, Cornelius V, Warnock A, et al. Effectiveness of mood stabilizers and antipsychotics in the maintenance phase of bipolar disorder: a systematic review of randomized controlled trials. Bipolar Disord. 2007;9(4):394-412.

24. Licht RW, Gijsman H, Nolen WA, et al. Are antidepressants safe in the treatment of bipolar depression? A critical evaluation of their potential risk to induce switch into mania or cycle acceleration. Acta Psychiatr Scand. 2008;118(5):337-346.

25. 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.Epub 2008 Dec 16.

26. Sachs GS, Nierenberg AA, Calabrese JR, et al. Effectiveness of adjunctive antidepressant treatment for bipolar depression. N Engl J Med. 2007;356(17):1711-1722.

27. Thase ME, Madfadden W, Weisler RH, et al. Efficacy of quetiapine monotherapy in bipolar I and II depression: a double-blind, placebo-controlled study (the BOLDER II study). J Clin Psychopharmacology. 2006;26(6):600-609.

28. Geddes JR, Calabrese JR, Goodwin GM. Lamotrigine for treatment of bipolar depression: independent meta-analysis and meta-regression of individual patient data from five randomised trials. Br J Psychiatry. 2009;194:4-9.

29. Beynon S, Soares-Weiser K, Woolacott N, et al. Psychosocial interventions for the prevention of relapse in bipolar disorder: systematic review of controlled trials. Br J Psychiatry. 2008;192(1):5-11.

30. Scott J, Paykel E, Morriss R, et al. Cognitive-behavioural therapy for severe and recurrent bipolar disorders: randomised controlled trial. Br J Psychiatry. 2006;188(4):313-320.

31. Miklowitz DJ. Adjunctive psychotherapy for bipolar disorder: state of the evidence. Am J Psychiatry. 2008;165(11):1408-1419.Epub 2008 Sep 15.

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Comment on this article

At least 25% and possibly up to 50% of patients with recurrent major depressive disorder (MDD) have features of mild hypomania (the “soft end” of the bipolar spectrum¹) and might be better conceptualized as suffering from a broadly defined bipolar (BP) II disorder.² The challenge is to differentiate MDD from BP II so that we make treatment decisions—such as antidepressants vs mood stabilizers—shown to improve the long-term course of patients’ depressive symptoms.

Diagnosis of BP II often is not straightforward and unfortunately may be delayed several years after patients first present for evaluation. To help clinicians make correct diagnostic decisions, this article:

describes diagnostic criteria outside of DSM-IV-TR that can assist in identifying BP II disorder
identifies subgroups of recurrently depressed patients whose primary disorder is more likely to be bipolar than unipolar
provides a screening tool validated for identifying “soft” bipolarity
offers a pragmatic clinical perspective on the treatment of BP II disorder.

How common is BP II disorder?

As with all psychiatric diagnoses, the prevalence of BP II disorder is a function of the diagnostic criteria used to define it.³ BP II—1 or more depressive episodes with at least 1 hypomanic episode—affects 1% to 2% of the population, based on DSM-IV-TR criteria for hypomania (Box 1). However, the DSM definition of BP II might be too restrictive. Regarding the diagnosis of hypomania, in particular:

Clinical Point

Instead of DSM’s 4-day threshold, at least 1 day’s duration would be a more realistic definition of hypomania in BP II disorder

the symptom of “overactivity” should be given as much weight as the stem criteria of “euphoria” and “irritability”
the 4-day threshold for a hypomanic episode probably is too long.

The fact that DSM-IV-TR does not associate hypomania with marked functional impairment is somewhat counterintuitive. Most clinicians would agree that functional impairment is a useful criterion for clinical diagnosis of any psychiatric syndrome.

These deficiencies in DSM-IV-TR exclude many patients who experience brief but clinically significant periods of hypomania. A more realistic definition of hypomania within BP II disorder would:

include overactivity as an additional stem criterion
specify a threshold duration for hypomanic symptoms of at least 1 day rather than 4 days
stipulate the experience of negative consequences of the episode as necessary for the diagnosis (Table 1).

In long-term follow-up studies of several thousand individuals, Angst et al⁴ demonstrated that this definition of hypomania is clinically valid in terms of bipolar family history, treatment response, illness course, and clinical characteristics. When this broader definition of hypomania is used, population prevalence estimates for BP II rise from 1% to 2% to at least 5%.⁵

Box 1

DSM-IV-TR criteria for a hypomanic episode

A distinct period of persistently elevated, expansive, or irritable mood, lasting at least 4 days, that is clearly different from the usual nondepressed mood
During the period of mood disturbance, 3 or more of the following symptoms have persisted (4 if the mood is only irritable) and have been present to a significant degree:
The episode is associated with an unequivocal change in functioning that is uncharacteristic of the person when not symptomatic
The disturbance in mood and the change in functioning are observable by others
The episode is not severe enough to cause marked impairment in social or occupational functioning, or to necessitate hospitalization, and there are no psychotic features
The symptoms are not due to the direct physiological effects of a substance (a drug of abuse, a medication, or other treatment) or a general medical condition (such as hyperthyroidism)

Note: Hypomanic-like episodes that are clearly caused by somatic antidepressant treatment (such as medication, electroconvulsive therapy, or light therapy) should not count toward a diagnosis of bipolar II disorder

Table 1

Proposed hypomania criteria in broadly defined BP II

A. Euphoria, irritability, or overactivity
B. At least 3 of the 7 DSM-IV-TR symptoms of hypomania
C. Hypomanic symptoms of at least 1 day’s duration
D. Experience of negative consequences of hypomanic periods
BP II: bipolar II disorder
Source: Reference 4

Depression’s subgroups

Recurrent MDD is an extremely heterogeneous diagnosis. It includes many clinical presentations of depressive illness that may share little in terms of etiology, pathophysiology, and response to treatment. When carefully assessed, 2 subgroups of recurrently depressed patients in particular appear to be more likely to have a primary bipolar disorder:

young patients with early-onset severe depression
older adults with difficult-to-treat or treatment-resistant depression.

A 15-year follow-up of young adults hospitalized with unipolar depression found that 27% subsequently developed hypomania and an additional 19% experienced at least 1 episode of mania.