Treatment-resistant bipolar disorder: a comparison of rapid cyclers and nonrapid cyclers

We investigated clinical factors to determine their relationship to treatment resistance among bipolar patients who had a consultation at a tertiary care facility.

Patients were separated into two categories: rapid-cycling disorders and nonrapid-cycling disorders. We hypothesized that there would be less usage of lithium carbonate among nonrapid-cycling treatment-resistant patients than among rapid cyclers and also that there would be higher rates of comorbidity seen among nonrapid-cycling than rapid-cycling patients in order to account for these particular patients being treatment resistant.

Continued recycling and persistent depression characterized rapid cyclers, whereas persistent depression characterized nonrapid cyclers. Less than 30% of patients had adequate lithium treatment and there was no significant difference comparing rapid cyclers with nonrapid cyclers. Rates of comorbidity were also not significantly different between these groups. We also assessed a number of other factors.

Some of these factors were significant, but when a Bonferonni correction was applied, these significant differences were not maintained. The study of treatment resistance among nonrapid-cycling bipolar patients merits further research.