Depression and decision-making capacity for treatment or research: a systematic review

Abstract

BackgroundPsychiatric disorders can pose problems in the assessment of decision-making capacity (DMC). This is so particularly where psychopathology is seen as the extreme end of a dimension that includes normality. Depression is an example of such a psychiatric disorder. Four abilities (understanding, appreciating, reasoning and ability to express a choice) are commonly assessed when determining DMC in psychiatry and uncertainty exists about the extent to which depression impacts capacity to make treatment or research participation decisions.MethodsA systematic review of the medical ethical and empirical literature concerning depression and DMC was conducted. Medline, EMBASE and PsycInfo databases were searched for studies of depression and consent and DMC. Empirical studies and papers containing ethical analysis were extracted and analysed.Results17 publications were identified. The clinical ethics studies highlighted appreciation of information as the ability that can be impaired in depression, indicating that emotional factors can impact on DMC. The empirical studies reporting decision-making ability scores also highlighted impairment of appreciation but without evidence of strong impact. Measurement problems, however, looked likely. The frequency of clinical judgements of lack of DMC in people with depression varied greatly according to acuity of illness and whether judgements are structured or unstructured.ConclusionsDepression can impair DMC especially if severe. Most evidence indicates appreciation as the ability primarily impaired by depressive illness. Understanding and measuring the appreciation ability in depression remains a problem in need of further research.

The Ethics of Clinical Trials Research in Severe Mood Disorders

“…Scales such as the MacCAT-CR 13 —which assess decisional capacity as it relates to appreciation, understanding, and reasoning in a research setting—have been vital to empirical studies on decision-making capacity. A recent review examining studies of decision-making capacity in depression, either in the context of treatment or research, concluded that most subjects with depression have adequate decision-making capacity, although depression appears to have the greatest impact on an individual’s ability to appreciate available options 14 . Although one study reported that depressed inpatients showed significant impairments in the abilities needed for decision-making capacity compared to inpatients with non-psychiatric illnesses, this report included subjects who had been involuntarily committed and who had other features, such as psychosis 15 .…”

Considering Consent to Research for Patients in Chronic Pain and With Mental Illnesses

“…Hindmarch, Hotopf, and Owen (2013) reported that “[t]he empirical studies reporting decision-making ability scores also highlighted impairment of appreciation but without evidence of strong impact” (p. 1).…”

New use for an old drug: oral ketamine for treatment-resistant depression

“…TRD is associated with increased morbidity and mortality7 8 and can negatively impact an individual's ability to participate in medical decision-making 9 10. Patients with TRD are twice as likely to be hospitalised with overall medical costs estimated at six times that of patients without TRD 5.…”