In general, there’s now cautious agreement that antidepressants can be used in bipolar depression. Antidepressants are commonly used in practice in combination with either mood stabilizers or atypical antipsychotics such as olanzapine. The rate of switching is lower than initially suspected. What’s emerging most recently is that there appears to be subsets of bipolar depression with certain characteristics that respond better to anti-depressant use than other groups. Some recent studies are focusing on determining what those characteristics are in order to guide clinicians’ use of antidepressants in the bipolar population.
First, some classes of antidepressants appear to be more efficacious. SSRIs are recommended while tricyclics should probably be avoided. Buproprion is still considered to be a first-line antidepressant. Antidepressants that have shown a previous response in a given patient are likely safe to use.
Some interesting findings: frequency of episodes is negatively correlated with response to antidepressants, whereas severity of episodes is not. There’s also a trend toward better response to antidepressants in those presenting with psychotic features. Another interesting finding is a negative correlation with the number of hypomanic episodes — the more hypomanic episodes the less effective the treatment with antidepressants. Overall the risk of a switch to mania seems less worrisome than was suspected for many years except in those who are frequent switchers. There’s even some evidence that continuing with antidepressant treatment in bipolar depressed responders should continue for 6 months to 1 year following the depressed episode. The treating clinician should remember that lamotrigine or quetiapine have been shown to be as effective as monotherapy or in combination with other mood stabilizers for the treatment of bipolar depression.