NEW YORK (Reuters Health) Jun 08 - Patients with bipolar disorder can have difficulty in decision making in the informed consent process, but that does not mean that these patients are incompetent, investigators at the University of California at San Diego report in the May Journal of Clinical Psychiatry.

Dr. Barton W. Palmer and colleagues evaluated the decisional capacity of 31 outpatients with bipolar disorder, 31 outpatients with schizophrenia and 28 healthy controls. Capacity was measured using the MacArthur Competence Assessment Tool for Clinical Research and neurocognitive testing and based on clinical assessment.

Bipolar patients showed an impaired understanding compared with healthy controls. Their decisional capacity was equal to that of the schizophrenic patients.

The investigators found that "neurocognitive deficits and negative symptoms were significantly correlated with the level of decisional capacity (particularly understanding of disclosed information)." Repeating the missed information "improved the level of understanding in all groups."

Dr. Palmer suggested conducting consent as an interactive dialogue. The healthcare provider should "actively check the participant's understanding of key information by asking him or her to explain it in his or her own words, and then to re-explain that information and re-check the participant's understanding of that information," Dr. Palmer told Reuters Health.

"Within our outpatient sample, the variance in decisional capacity was best predicted by level of cognitive functioning," Dr. Palmer said. "This is important because of the fact that many people with bipolar disorder may have subtle cognitive deficits even during periods (of symptom control)...This has not been widely appreciated or recognized until recently."

"Much less is known about the effect of acute manic or depressive symptoms, such as would be seen among patients in acute hospitalized settings," Dr. Palmer commented. "It seems rational to expect that acute manic symptoms would hinder the appreciation component of decisional capacity, but there remains a need for empirical research to find out for certain."