Capacity to provide informed consent among adults with bipolar disorder

Identifying correlates of capacity to provide informed consent among individuals with bipolar disorder is essential for patient protection. As part of a clinical trial involving approved, standard treatments, we investigated relationships between clinical characteristics and capacity to provide informed consent in adults with bipolar disorder using the MacArthur Competence Assessment Tool for Clinical Research (MacCAT-CR). After administering the MacCAT-CR, continuing participants in the trial were capable of and provided informed consent.

Trained, board-certified psychiatrists administered the MacCAT-CR to potential study participants (N = 50) after they provided informed consent, but prior to initiation of study procedures.

Higher Schedule for Assessment of Positive Symptoms (SAPS) scores were significantly correlated with worse MacCAT-CR Understanding and Appreciation (p < 0.04) subscale scores; lower Hamilton Depression Rating Scale (HDRS) scores and higher Clinical Global Impression-Severity (CGI-S) scores were significantly correlated with worse Reasoning and Understanding subscale scores (p < 0.03); and patients with comorbid substance use disorders (SUD) had better Appreciation and Reasoning subscale scores (p < 0.05).

The MacCAT-CR identifies areas where participants need explanation. However, there is not a predetermined score to indicate understanding of study procedures and therefore input from a trained clinician is needed to determine capacity to provide informed consent.

Our findings suggest that certain measures of illness severity are associated with lower levels of capacity to provide informed consent among adults with bipolar disorder. This study provides important information for clinicians and researchers to consider when obtaining informed consent in this population.