Treatment of Bipolar Depression

Treatment of Bipolar Depression

The algorithm presented for treatment-resistant bipolar depression (Figure 45-3) attempts to balance the need for antidepressant treatment and the risk of treatment-induced mania or rapid cycling. These treatments are started at the time of diagnosis (i.e., the acute phase).

Each individual acute treatment trial is carried out to one of three endpoints:

Discontinuation because the patient is unable to tolerate the adverse effects of treatment

Discontinuation because the patient has not responded to a maximal trial of the treatment (including, if warranted, augmentation strategies)

Treatment success (i.e., the patient has improved during this treatment)

In the case of treatment success, therapy should be continued for a period of time to prevent relapse (i.e., continuation phase). At the conclusion of the continuation phase, acute treatments are gradually tapered and the patient is maintained on a treatment regimen intended to prevent recurrence. Relapse during the taper period should be managed by resumption of acute-phase strategies. Antidepressant doses should be raised to effective levels and another taper attempted following another continuation phase.

For most patients, maintenance treatment with antidepressants should be avoided. However, because a substantial number of individuals with bipolar illness are subject to frequent severe depressive relapses (Altshuler 1999), a prophylactic regimen that includes an antidepressant as well as a mood stabilizer may be optimal for patients with a history of multiple relapses during attempts to discontinue their antidepressant treatment. For such cases in which antidepressants are made a part of the prophylactic regimen, it is prudent to seek the lowest effective dose.

Use of Lithium
Although 8 of 10 early studies showed that lithium had greater antidepressant efficacy than placebo, this may not establish lithium as equivalent in efficacy to other antidepressants. The traditional antidepressants may be more effective than lithium in treating bipolar depression. For instance, the only direct comparison of lithium and a standard antidepressant with a sample consisting of more than four patients demonstrated that the effect of imipramine was greater, but the statistical significance of this finding is unclear (Fieve et al. 1968). However, among unselected patients in open practice, use of lithium monotherapy appears to be sufficient therapy for about one-third to two-thirds of bipolar depressed patients (Sachs et al. 1994b). Furthermore, patients whose illness is effectively treated by lithium are spared the risk of antidepressant-induced mania.