Bipolar disorder is classified into subcategories that are dependent on the type of episode, manic or depressive, its severity and rate of recurrence. The "Diagnostic and Statistical Manual of Mental Disorders" classifies persons with bipolar disorder type 2 as those who have not had a manic episode, but have had one or more hypomanic episodes and at least one major depressive episode. The diagnosis of bipolar disorder type 2 is difficult because hypomanic episodes, which are characterized by an elevation in mood and productivity, but unaccompanied by the more debilitating manic symptoms of psychosis, are reported infrequently. The Harvard South Shore Program and The World Federation of Societies of Biological Psychiatry, or WFSBP, have developed the most recent treatment guidelines for bipolar depression.
Mood Stabilizing Drugs
Mood stabilizing drugs include lithium, lamotrigine and carbamazepine. The Harvard treatment guidelines recommend lithium as the first line of treatment, but if it is not effective or tolerated, patients may be treated with quetiapine or lamotrigine. Quetiapine is an atypical antipsychotic, but is also an effective mood stabilizer. Other mood stabilizing drugs, like valproate, are ineffective in treating depression, but are useful for the treatment of hypomania. The Harvard guidelines state that the combinations of two or three mood stabilizers may be required to treat persons who rapidly cycle between episodes of depression and hypomania.
Atypical Antipsychotics
The WFSBP treatment guidelines state that atypical antipsychotics are beneficial in treating psychosis in bipolar patients, and trials have shown that olanzapine and risperidone also have antidepressant effects. Neither the WFSBP or Harvard treatment guidelines suggest atypical antipsychotics as front-line treatments for depression, but cite evidence for their effectiveness in combination with a mood stabilizing drug. A review in the journal, "Bipolar Disorders," reports that the atypical antipsychotic, olanzapine, olanzapine in combination with the antidepressant, fluoxetine, and quetiapine are effective in the treatment of bipolar depression. A review in "Central Nervous System Drugs" reports that the second-generation antipsychotics, olanzapine, quetiapine, risperidone, ziprasidone and aripiprazole are effective in treating the hypomanic symptoms of persons with bipolar disorder type 2.
Antidepressants
The WFSBP cites evidence that newer-generation antidepressants, such as selective serotonin reuptake inhibitors or bupropion, in combination with mood stabilizing drugs, may be effective in treating depression in patients with bipolar disorder; however, most research has been conducted in unipolar patients. Both the WFSBP and Harvard guidelines state that antidepressants may induce switching between episodes, or rapid cycling, although the evidence is controversial.
Electroconvulsive Therapy
The WFSBP and Harvard treatment guidelines state that there is evidence to support that electroconvulsive therapy, or ECT, is effective in treating bipolar depression that is severe and accompanied by psychosis, and in persons that do not respond to drug combination therapy.
References
- BehaveNet: DSM-IV and DSM-IV-TR: Bipolar II Disorder
- "Harvard Review of Psychiatry"; The Psychopharmacology Algorithm Project Update of Bipolar Depression; Arash Ansari; 2010
- PubMed: Bipolar II Disorder: Epidemiology, Diagnosis and Management
- PubMed: Pharmacotherapy of Bipolar II Disorder: A Critical Review of Current Evidence
- The World Federation of Societies of Biological Psychiatry: WFSBP Treatment Guidelines on Bipolar Disorders
