The Mental Health Act (MHA) 2001 has major implications for treating patients with electroconvulsive therapy (ECT), especially as those referred for treatment are among the most severely ill and often lose capacity. Under the MHA 2001, a person may only be treated without consent if they are an involuntary patient. However, there is no provision in the Act for treating voluntary inpatients whose mental state has deteriorated but who do not seek to leave hospital. Such people may lack capacity to make treatment decisions but be passively compliant.

The Wards of Court system is currently the only legal recourse but has been criticised by the Law Reform Commission and is unwieldy. Further legislation governing treatment of people lacking capacity to consent to ECT or withhold consent is required to protect and advance treatment of all concerned.

Informed consent is key to ethical clinical research and treatment, but partially rests on the ability of individual patients or research participants to use disclosed information to make a meaningful choice. Although the construct of decisional capacity emerged from legal and philosophical traditions, several investigators have begun examining the relationship of specific neuropsychological abilities to decisional capacity. This line of research may foster development of better consent procedures, as well as aid in refining the construct of decisional capacity toward a form that better reflects the underlying neurocognitive processes. We conducted a systematic search of the published literature and thereby identified and reviewed 16 published reports of empirical studies that examined the relationship between specific neuropsychological abilities and capacity to consent to research or treatment. Significant relationships between neuropsychological scores and decisional capacity were present across all the reviewed studies. The degree to which specific neuropsychological abilities have particular relevance to decisional capacity remains uncertain, but the existing studies provide a solid basis for a priori hypotheses for future investigations. These ongoing efforts represent an important conceptual and empirical bridge between bioethical, legal, and neuropsychological approaches to understanding meaningful decision-making processes. (JINS, 2007, 13, 1047–1059.)