Soft bipolarity: how to recognize and treat bipolar II disorder

At least 25% and possibly up to 50% of patients with recurrent major depressive disorder (MDD) have features of mild hypo-mania (the end of the bipolar spectrum (1)) 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. [ILLUSTRATION OMITTED] [ILLUSTRATION OMITTED] 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, page 42). However, the DSM definition of BP II might be too restrictive. Regarding the diagnosis of hypomania, in particular: Box 1 DSM-IV-TR criteria for a hypomanic episode A. A distinct period of persistently elevated, expansive, or irritable mood, lasting at least 4 days, that is clearly different from the usual nondepressed mood B. 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: 1) inflated self-esteem or grandiosity 2) decreased need for sleep 3) more talkative than usual or pressure to keep talking 4) flight of ideas or subjective experience that thoughts are racing 5) distractibility 6) increase in goal-directed activity or psychomotor agitation 7) excessive involvement in pleasurable activities that have potential for painful consequences C. The episode is associated with an unequivocal change in functioning that is uncharacteristic of the person when not symptomatic D. The disturbance in mood and the change in functioning are observable by others E. 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 F. 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 * the symptom of 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 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). …