competence, consent, anorexia, appreciation, decision making
Tan and her colleagues (2006) reported that persons with anorexia nervosa typically manifest no difficulty satisfying the criteria for abilities associated with competence to consent to or refuse treatment. Their results led them to conclude that these patients generally had no problem grasping the nature of anorexia and its possible consequences (understanding), typically did not have difficulty processing information when making treatment decisions (reasoning), and usually neither denied that they had a disorder nor manifested distorted beliefs about the potential consequences of treatment for the disorder.
Nevertheless, these authors found, some anorexia patients said that they knew they might die and that they would rather die than suffer the alternative consequences (e.g., loss of identity, feeling of being disgusting). They point out that these beliefs, suggesting questionable competence, were not identified by the usual criteria for competence to consent to treatment. Therefore, they propose that we should consider a modification of the criteria for competence to consent to treatment. They argue for inclusion of "pathological values" as the basis for a finding of incompetence. Their notion of a pathological value (as we summarize it based on their Discussion) includes (a) a personal value (b) on which treatment refusal is based, that (c) is not authentic, and (d) is due to a mental disorder.
Second, Tan and colleagues were concerned that the MacArthur Competence Assessment Tool for Treatment (MacCAT-T), currently used widely to assess competence to consent to treatment, did not seem to take values into account when examining deficits related to lack of appreciation or reasoning. They point out that most patients with anorexia nervosa in their study had "pathological values" that influenced their thinking about treatment, yet they did not obtain poor scores on the instrument's appreciation scale, which assesses whether patients deny that they have the illness or offer reasons for accepting or refusing treatment that are based on delusional premises or a serious distortion of reality. Moreover, almost all of the anorexia patients in the study obtained adequate scores on reasoning, which examines the ability to process options and consequences when weighing a treatment decision. [End Page 293]
Reasons for Caution in Altering Criteria for Competence
A fundamental step in considering Tan and her co-worker's proposal is to examine whether it is necessary to add a concept of "pathological values" to the legal construct of competence to consent to treatment. Modifying the legal doctrine of consent is important if that is needed to improve its validity or reliability. But modifications of the doctrine would have considerable costs, including a long process of producing logical and empirical evidence for its necessity, developing methods to assess the new concept, and then a process of debate, persuasion, and education to change laws, ethical guidelines, and medical training. Moreover, principles of theory building urge parsimony. A theory should employ no more concepts or assumptions than are required to account for the phenomena that the theory seeks to organize or explain. So one must be sure that modifications are truly necessary before adding complexity to the theory of decisional competence.
In addition, there is an inherent danger in altering a concept like competence to consent to treatment on the basis of the study of any one mental disorder. It is not at all clear how the modification might influence findings of competence when applied to other disorders. Using a study of patients with anorexia nervosa as the impetus for changing the competence concept runs this risk. For example, anorexia is one of a class of mental disorders that is characterized by a failure to abstain from behavior (here, limiting food intake and other behaviors designed to reduce weight) that has negative consequences for the person. Other conditions in this category might include substance abuse disorders and impulse control disorders (e.g., pathological gambling). Even if one concludes that revised criteria for competence would reduce false-positive findings of competence in this group of disorders, one would have to consider carefully its impact on the full range of disabling mental conditions.
Moreover, the sensitivity...