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Diagnosis and Impact of Bipolar Depression

Charles L. Bowden, MD

Department of Psychiatry, University of Texas Health Science Center, and the Center for Bipolar Illness Interventions in Hispanic Communities, San Antonio

Misdiagnosis of Bipolar Disorder

A study1 conducted by the Depressive and Bipolar Support Alliance found that 69% of patients with bipolar disorder were initially misdiagnosed, and about a third of those initially misdiagnosed were symptomatic for 10 years or more before being diagnosed correctly. Since most people with bipolar disorder have onset of illness during adolescence, most formal education will have been completed and adversely impacted by the illness before the person is started on the right course of treatment. If bipolar diagnosis does not happen until a person's mid-20s, many of the activities that lead to early career success and choice of a lifetime mate in a marriage or partnership may have occurred and been affected by the disorder before it is recognized and properly treated.

 

Bipolarity in Depressive Episodes

Patients with bipolar disorder usually seek treatment for depression and often do not spontaneously report the presence of clear hypomanic symptoms.2 Clinicians should carefully screen for indications of bipolar mania in all patients with depression or anxiety, especially those with early onset or persisting depression or anxiety or with a family history of bipolar disorder. Watch this brief video to gain insights into diagnosing bipolar disorder with patients experiencing depression (AV 1AV 1).

 

A study3 of 1,380 subjects with bipolar disorder evaluated the incidence of manic or hypomanic symptomatology during depressive episodes. Approximately two thirds of depressed patients had manic or hypomanic symptoms; racing thoughts and distractibility were the most common (AV 2AV 2). So, when evaluating patients with depression for bipolar disorder, the symptomatology to look for is not elation or grandiosity but rather distractibility and racing thoughts. One tool that clinicians could use to identify discrete behavioral components of bipolar disorder is the Bipolar Inventory of Symptoms Scale.4

Role Impairment and Course of Illness of Bipolar Disorder

 

Both mania/hypomania and depression cause severe role impairment for people with bipolar disorder, but those with depression have greater role impairment than those with mania in both bipolar I and II disorders.5 Additionally, subthreshold depressive symptoms in bipolar disorder are associated with almost as much impairment as full syndromal depressive symptomatology. However, subthreshold manic symptoms, ie, mild hypomania, were less likely to be associated with severe role impairment than full syndromal mania (AV 3AV 3).5 Thus, the distractibility and racing thoughts experienced in bipolar mania are not associated with as much dysfunction as even mild levels of bipolar depression.

Bipolar depression is more than just the other side of the bipolar coin from mania; that is, manic and depressive episodes may not alternate evenly. Depression is more likely to be repeated in subsequent episodes than mania. Two 18-month studies6,7 of subjects with bipolar I disorder who were currently or recently manic/hypomanic or depressed found that, of the subjects from the depressed group who developed a new mood episode, three quarters had a repeat depressive episode. By contrast, subjects with recent mania/hypomania displayed a small increase in the likelihood for the development of a new manic episode. In other words, depression is highly predictive of future depression, but mania is no more predictive of future mania than it is of future depression.

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Treatment Issues

Because of role impairment and other consequences of bipolar illness, appropriate treatment is crucial. However, the National Comorbidity Survey Replication study5 found that, of patients with bipolar disorder, only about 50% being treated by psychiatrists and only about 10% being treated by a doctor other than a psychiatrist received appropriate medications. Furthermore, 43% of patients being treated by psychiatrists and 73% of patients being treated by nonpsychiatric doctors received inappropriate medications as part of their treatment regimen. A better understanding of bipolar depression, its diagnosis, and its treatment will alleviate many of these problems.

For Clinical Use

  • Screen for manic or hypomanic symptoms, such as distractibility and racing thoughts, in all patients with depression or anxiety, especially those with early onset or persistent depression or anxiety or with a family history of bipolar disorder
  • Recognize that bipolar depressive episodes (even subsyndromal ones) tend to cause more role impairment than bipolar manic episodes
  • Some patients wait 10 or more years to be correctly diagnosed, and many patients with bipolar disorder do not receive appropriate medications but do receive inappropriate medications

Drug Names

bupropion (Aplenzin, Wellbutrin, and others), fluoxetine (Prozac and others), imipramine (Tofranil and others), lamotrigine (Lamictal and others), lithium (Lithobid, Eskalith, and others), olanzapine (Zyprexa), olanzapine-fluoxetine (Symbyax), paroxetine (Paxil, Pexeva, and others), quetiapine (Seroquel), venlafaxine (Effexor and others)

Abbreviations

DSM-IV = The Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition
STEP-BD = Systematic Treatment Enhancement Program for Bipolar Disorder

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References

  1. Hirschfeld RM, Lewis L, Vornik LA. Perceptions and impact of bipolar disorder: how far have we really come? results of the National Depressive and Manic-Depressive Association 2000 Survey of individuals with bipolar disorder. J Clin Psychiatry. 2003;64(2):161–174.
  2. Bowden CL. Strategies to reduce misdiagnosis of bipolar depression. Psychiatr Serv. 2001;52(1):51–55.
  3. Goldberg JF, Perlis RH, Bowden CL, et al. Manic symptoms during depressive episodes in 1,380 patients with bipolar disorder: findings from the STEP-BD. Am J Psychiatry. 2009;166(2):173–181.
  4. Gonzalez JM, Bowden CL, Katz MM, et al. Development of the Bipolar Inventory of Symptoms Scale: concurrent validity, discriminant validity and retest reliability. Int J Methods Psychiatr Res. 2008;17(4):198–209.
  5. Merikangas KR, Akiskal HS, Angst J, et al. Lifetime and 12-month prevalence of bipolar spectrum disorder in the National Comorbidity Survey Replication. Arch Gen Psychiatry. 2007;64(5):543–552. Correction in 2007;64(9):1039.
  6. Bowden CL, Calabrese JR, Sachs G, et al. A placebo-controlled 18-month trial of lamotrigine and lithium maintenance treatment in recently manic or hypomanic patients with bipolar I disorder. Arch Gen Psychiatry. 2003;60(4):392–400. Correction 2004;61(7):680.
  7. Calabrese JR, Bowden CL, Sachs G, et al, for the Lamictal 605 Study Group. A placebo-controlled 18-month trial of lamotrigine and lithium maintenance treatment in recently depressed patients with bipolar I disorder. J Clin Psychiatry. 2003;64(9):1013–1024.
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