Assessment of decisional capacity: Prevalence of medical illness and psychiatric comorbidities.

OBJECTIVE: Studies on decisional capacity have primarily focused on cognitive disorders, whereas noncognitive disorders remain understudied. The purpose of our study was to assess decisional capacity across a wide spectrum of medical and psychiatric disorders.
METHOD: More than 2,500 consecutive consults were screened for decisional capacity, and 336 consults were reviewed at Bellevue Hospital Center in New York. Sociodemographic and medical variables, medical and psychiatric diagnoses, as well as decisional capacity assessments were recorded and analyzed.
RESULTS: Consults for decisional capacity were most commonly called for in male patients with cognitive and substance abuse disorders. Less commonly, consults were called for patients with mood or psychotic disorders. Overall, about two thirds of patients (64.7%) were deemed not to have decisional capacity. Among medical diagnoses, neurological disorders contributed to decisional incapacity, and among the psychiatric diagnoses, cognitive disorders were most frequently documented in cases lacking decisional capacity (54.1%) and interfered more commonly with decisional capacity than substance abuse or psychotic disorders (37.2 and 25%). In contrast, patients with mood disorders usually retained their decisional capacity (32%). Generally, the primary treatment team's assessment was accurate and was confirmed by the psychiatric service. SIGNIFICANCE OF
RESULTS: Although decisional capacity assessments were most commonly requested for patients with substance abuse and cognitive disorders, the latter generally affected the ability to make healthcare decisions the most. Further, cognitive disorders were much more likely to impair the ability to make appropriate healthcare decisions than substance abuse or psychotic disorders.