Influence of mood state on capacity to consent to research in patients with bipolar disorder.

OBJECTIVES: Experts have debated the ability of patients with bipolar illness to consent to research participation when manic. We compared 25 euthymic bipolar and 26 manic bipolar patients in their understanding of three hypothetical studies of varying complexity.
METHODS: Hypothetical studies were presented as written informed consent forms, which were reread up to three times. Questions included assessment of hypothetical study purposes, procedures, risks and benefits, and voluntariness of participation.
RESULTS: After adjusting for educational level, subjects with mania had lower mean understanding scores for all three hypothetical studies compared to euthymic subjects on initial assessment. By the end of Trial 3 of each hypothetical study, there were no significant differences between groups. The proportion of subjects with mania who met predetermined pass criteria for sufficient understanding was lower than the proportion of euthymic subjects on initial assessment of the first hypothetical study, but not the other hypothetical studies (odds ratio = 0.24; 95% confidence interval = 0.07-0.8; p = 0.02). Both groups exhibited an increase in the pass proportion by the end of the third trial for each hypothetical study with no significant differences between groups.
CONCLUSIONS: We conclude that subjects with mania exhibited significantly poorer levels of understanding of relevant information in hypothetical research consent forms compared to euthymic subjects when initially presented with research information. The improvement in manic patients' understanding scores with the iterative review of consent forms suggests that many manic patients may be able to consent to research protocols containing an educational intervention as a part of the informed consent process.