Mental health law and the UN Convention on the rights of Persons with Disabilities.

People with a mental illness may be subject to the UN Convention on the Rights of Persons with Disabilities (CRPD), depending on definitions of terms such as 'impairment', 'long-term' and the capaciousness of the word 'includes' in the Convention's characterisation of persons with disabilities. Particularly challenging under the CRPD is the scope, if any, for involuntary treatment. Conventional mental health legislation, such as the Mental Health Act (England and Wales) appears to violate, for example, Article 4 ('no discrimination of any kind on the basis of disability'), Article 12 (persons shall 'enjoy legal capacity on an equal basis with others in all aspects of life') and Article 14 ('the existence of a disability shall in no case justify a deprivation of liberty'). We argue that a form of mental health law, such as the Fusion Law proposal, is consistent with the principles of the CRPD. Such law is aimed at eliminating discrimination against persons with a mental illness. It covers all persons regardless of whether they have a 'mental' or a 'physical' illness, and only allows involuntary treatment when a person's decision-making capability (DMC) for a specific treatment decision is impaired - whatever the health setting or cause of the impairment - and where supported decision making has failed. In addition to impaired DMC, involuntary treatment would require an assessment that such treatment gives the person's values and perspective paramount importance.