Adjunctive dopamine agonists in treatment-resistant bipolar II depression: an open case series

Previous studies and case observations have suggested that dopamine agonists (DAAs) such as pramipexole (PPX) and ropinirole (RPN) might be effective for major depression, but their adjunctive use in treatment-resistant bipolar II depression has not yet been specifically addressed.

A chart review was conducted on 18 patients with a DSM-III-R bipolar NOS (Bipolar II) major depressive episode who were admitted to the day-hospital of the Department of Psychiatry at the University of Pisa. DAAs were added to ongoing treatments with conventional antidepressants and mood stabilizers to which patients had no responded after a period of at least 8 weeks. Clinical state and adverse effects were assessed at each visit. Final improvement in CGI scores of 1 or 2 were considered as responders.

Mean DAA trial duration was 17.6 (sd = 7.8, range 4-34) weeks, with a mean final dose of 1.23+/-0.32 mg/day (range, 0.75-1.50mg/day) for PPX, and 2.97+/-0.99mg/day (range, 1.50-5.00mg/day) for RPN. DAAs were well tolerated and did not show any negative interaction with concomitant psychotropic medications. Only one patient became worse (final CGI = 5), and had to interrupt PPX due to nausea, increased agitation and irritability. Eight patients (44.4%) were considered responders (4 with PPX and 4 with RPN): 5 showed marked improvement (CGI = 1), and 3 showed moderate improvement (CGI = 2); another 5 (27.8%) manifested a transient response not sustained up to the end. The initial and final scores of CGI severity scale for all patients (responders and non-responders combined) were, respectively, 5.33+/-0.7 and 3.94+/-1.3 (mean +/- S.D). The mean change according to the CCI severity scale was statistically significant (t=4.74. p < 0.0002).

From the results, PPX and RPN appear to be well tolerated and potentially useful in the adjunctive treatment of drug-resistant bipolar II depression.