A comparative analysis of the intersection of mental capacity laws and international human rights law in Northern Ireland and Ireland

This article examines the law on mental capacity in Ireland and Northern Ireland. It sets out key provisions in the Mental Capacity Act (Northern Ireland) 2016 (MCA (NI)) and the Assisted Decision-Making (Capacity) Act 2015 (ADMCA). The slow legislative progress in Ireland and Northern Ireland requires closer examination, particularly due to the unique links between the jurisdictions. Both Northern Ireland and Ireland have ratified the United Nations (UN) Convention on the Rights of Persons with Disabilities (CRPD), and this article considers how both legislative models align with human rights obligations under the CRPD. The ‘fusion‘ model of legislation adopted in Northern Ireland represents an experimental approach, retaining provisions on substitute decision-making but placing a greater emphasis on supporting persons to make decisions. The legislation in Ireland also adopts an experimental approach placing a premium on supported decision-making, while also retaining substitute decision-making provisions. The article evaluates the jurisprudence of the Committee on the Rights of Persons with Disabilities on article 12, using it as a lens to assess the MCA (NI) and the ADMCA. By comparing the principles underpinning the legislative frameworks, best interests in the MCA (NI) and will and preferences in the ADMCA, and the different approaches to capacity assessment, this article argues that the ADMCA aligns better with the CRPD’s requirements. The ADMCA in Ireland and the fusion model in Northern Ireland are gaining international attention for their experimental approaches to capacity legislation reform and seeking alignment with article 12 of the CRPD. While these models aim to enhance autonomy, respect human rights and move away from restrictive systems, their effectiveness in practice requires further research to identify operational challenges and ensure alignment with the CRPD. These models offer valuable insights for global capacity law reform initiatives.