Defining Decisional Incapacity

Tarris Rosell, DMin, PhD
Rosemary Flanigan Chair
Center for Practical Bioethics

We recently received a request to define limited/partial/diminished decisional capacity and found that such a definition is not as easy as one might think.

There are many definitions available of what it means to have and to assess capacity. The definitional problem is that limited/partial/diminished (and transient) all fall on a spectrum between full and no capacity, and is context/decision specific.

One resource can be found at www.apa.org/pi/aging/.../capacity-psychologist-handbook.pdf. Otherwise I suggest these definitions:

Full decisional capacity means that an individual has sufficient . . .

· knowledge with understanding (of relevant information, including risks and benefits)
· voluntariness without coercion,
· decisionality (ability to choose between options)
· communicability (ability to communicate choices made)

So as to be able to make all types of life decisions for oneself.

Limited, partial, or diminished capacity means that an individual has insufficient knowledge, voluntariness, decisionality, and/or communicability so as not to be able to make some types of life decisions for oneself.

Capacity or incapacity is always in relation to the type of decision to be made. Decisions involving higher risk and/or lower benefit require more sufficiency of knowledge with understanding and voluntariness without coercion. Decisions involving lower risk and/or higher benefit require less sufficiency of knowledge with understanding and voluntariness without coercion.

Decisionally incapacitant means that an individual has insufficient knowledge, voluntariness, decisionality, and/or communicability so as not to be able to make any type of life decision for oneself.

What do you think?