 However, a more neglected question (at least in the literature on informed consent) is the question of whether factors internal to the person can undermine voluntariness. If so, what are these factors and how do we identify them? If such factors exist, then they may most usefully be discussed in connection with decisional capacity as opposed to external topics like coercion. This is because questions about internal psychological barriers bring us back once more to questions about the particular abilities of the individual patient or subject, and because if there are problems here, their presence and extent are most likely to be assessed by clinicians. Arguably, just as failure to grasp the facts of the situation can make a choice meaningless, something like addiction—which in certain contexts almost guarantees that the person will choose in a particular way—may also thereby make choice meaningless (Charland 2002, 2011).