1 Istanbul Declaration on the Use and Effects of Solitary Confinement, 9 December 2007 (Istanbul Declaration).

2 Solitary confinement has been used by CIA: see George Tenet, “Guidelines on Interrogations Conducted Pursuant to the Presidential Memorandum of Notification of 17 September 2001”, The Torture Database, American Civil Liberties Union (ACLU), 16 August 2021, available at: https://tinyurl.com/hyhf3jjh (all internet references were accessed in March 2022). It has also has been used by the KGB: see Hinkle, Lawrence E. and Wolff, Harold George, “Communist Interrogation and Indoctrination of ‘Enemies of the States’: Analysis of Methods Used by the Communist State Police (a Special Report)”, AMA Archives of Neurology and Psychiatry, Vol.33, No. 9, 1956Google Scholar. Solitary confinement has also been used in various countries: see Peru, Decree Law No. 25475, Art. 20 (this rule was in force until the approval of Supreme Decree No. 005-97-JUS, 24 June 1997); Pakistan Penal Code, Act XLV, 1860, Art. 73, available at: www.wipo.int/wipolex/es/text.jsp?file_id=315426; Law of Penal Execution of the Federative Republic of Brazil, Arts 53, 58, in Penitentiary and Penal Enforcement Legislation in Comparative Law, May 2005, available at: www.pj.gov.py/ebook/libros_files/coleccion_de_derecho_penitenciario_4.pdf; German Law on the Execution of Custodial Sentences and Custodial Measures for Improvement and Security, Art. 89, in Penitentiary and Penal Enforcement Legislation in Comparative Law, May 2005, available at: http://www.pj.gov.py/ebook/libros_files/coleccion_de_derecho_penitenciario_4.pdf; Penal Code of Austria, Art. 103(2)(4), in Weil, Gotshal and Manges, Seeing into Solitary: A Review of the Laws and Policies of Certain Nations regarding Solitary Confinement of Detainees, Weil, New York, 2016, p. 24; Interim Report of the Special Rapporteur on Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment, UN Doc. A/64/215, 3 August 2009, para. 53.

3 See Morris, Norval and Rotham, David (eds), The Oxford History of the Prison: The Practice of Punishment in Western Society, Oxford University Press, Oxford, 1998Google Scholar; Scharff, Peter, “The Effects of Solitary Confinement on Prison Inmates: A Brief History and Review of the Literature”, Crime and Justice, Vol. 34, No. 1, 2006, p. 441Google Scholar; Peter Scharff, “Solitary Confinement: History, Practice, and Human Rights Standards”, Prison Service Journal, No. 181, 2009, p. 3. See also Foucault, Michael, Discipline and Punish: The Birth of the Prison, Vintage Books, New York, 1995Google Scholar; Colvin, Mark, Penitentiaries, Reformatories, and Chain Gang:. Social Theory and the History of Punishment in Nineteenth-Century America, St. Marvin Press, New York, 1997Google Scholar; Scharff, Peter, “A Religious Technology of the Self: Rationality and Religion in the Rise of the Modern Penitentiary”, Punishment and Society, Vol. 6, No. 2, 2004Google Scholar.

4 Convention on the Rights of Persons with Disabilities, UNGA Res. 61/106, 30 March 2007 (entered into force 3 May 2008), Art. 1.

5 At the level of conventional sources of international law, there is no universal definition of solitary confinement. On the other hand, soft-law instruments (declarations, resolutions and principles) have developed a wide legal framework on the use of solitary confinement. Thus, in the Istanbul Declaration, above note 1, solitary confinement is defined as the physical and social isolation of persons who remain confined to their cells for 22–24 hours a day. The Special Rapporteur on Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment shares the definition of the Istanbul Declaration in the Report of the Special Rapporteur on Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment, UN Doc. A/63/175, 28 July 2008, para. 77; Report of the Special Rapporteur on Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment, UN Doc. A/66/268, 5 August 2011, para 25; Report of the Special Rapporteur on Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment, UN Doc. A/HRC/22/53, 11 February 2013. The present paper will follow the definition outlined in the Istanbul Declaration.

6 This paper recognizes the definition of person with a psychosocial or mental disability according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5); however, the paper will cover the legal angle of persons with psychosocial disabilities and not the mental health angle.

7 These concepts will be explained in later sections.

8 Declaration of the Rights of Mentally Retarded Persons, UN Doc. A/8429, 21 September–22 December 1971, p. 93.

9 Ibid., preambular para. 1.

10 Declaration on the Rights of Disabled Persons, UNGA Res. 3447 (XXX), 9 December 1975.

11 Ibid., Art. 9.

12 Ibid., Art. 6. This article emphasizes the medical model of disability.

13 Principles for the Protection of the Mentally Ill and the Improvement of Mental Health Care, UN Doc. 46/119, 17 December 1991.

14 World Conference on Human Rights, Vienna, 14–25 June 1993. The conference produced the Vienna Declaration.

15 Standard Norm 64 of the Vienna Declaration. See also Regulations 63 and 65 concerning the rights of persons with disabilities.

16 See, for example, Committee on Economic, Social and Cultural Rights, “General Comment No. 5 (Persons with Disabilities)”, UN. Doc. E/C.12/1994/13, 25 November 1994.

17 International Covenant on Civil and Political Rights, UNGA Res. 2200A (XXI), 16 December 1966 (entered into force 23 March 1976).

18 International Covenant on Economic, Social and Cultural Rights, UNGA Res. 2200A (XXI), 16 December 1966 (entered into force 3 January 1976).

19 International Convention on the Elimination of All Forms of Racial Discrimination, UNGA Res. 2106A (XX), 21 December 1965 (entered into force 4 January 1969).

20 Convention on the Elimination of All Forms of Discrimination against Women, UN Doc. 34/180, 18 December 1979 (entered into force 3 September 1981).

21 Convention against Torture and Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment, UN Doc. 39/46, 10 December 1984 (entered into force 26 June 1987) (CAT).

22 Convention on the Rights of the Child, UN Doc. 44/25, 20 November 1989 (entered into force 2 September 1990).

23 International Convention on the Protection of the Rights of All Migrant Workers and Members of Their Families, UN Doc. 45/158, 18 December 1990 (entered into force 1 July 2003).

24 International Convention for the Protection of all Persons from Enforced Disappearance, UN Doc. A/61/53, 29 June 2006 (entered into force 23 December 2010). Additionally, the International Labour Organization established its own treaty regarding persons with disabilities: Vocational Rehabilitation and Employment (Disabled Persons) Convention, No. 159, 20 June 1983 (entered into force 20 June 1985).

25 Kanter, Alerne, The Development of Disability Rights under International Law: From Charity to Human Rights, Routledge, New York, 2015, p. 24Google Scholar.

26 Agustina Palacios, “El modelo social de la discapacidad”, in Elizabeth Salmón and Renata Bregaglio (eds), Nueve conceptos claves para entender la Convención sobre los Derechos de las Personas con Discapacidad, IDEHPUCP, Lima, 2015, pp. 10–12.

27 Palacios, Agustina, El modelo social de discapacidad: Orígenes, caracterización y plasmación en la Convención Internacional sobre los Derechos de las Personas con Discapacidad, Cinca, Madrid, 2008, p. 97Google Scholar.

28 Ibid., p. 97.

29 Ibid., p. 97.

30 Rafael de Asís Roig, “La incursión de la discapacidad en la teoría de los derechos: Posibilidad, educación, derecho y poder”, in Ignacio Campoy (ed.), Los derechos de las personas con discapacidad: Perspectivas sociales, jurídicas y filosóficas, Dykinson, Madrid, 2004, p. 62.

31 Denholm, Carey, McGowan, Phil and Tatham, Peter, “Emerging from the Shadows: Fijian Children and Youth with Disabilities”, in Baine, David, Brown, Roy I. and Neufeldt, Aldred H. (eds), Beyond Basic Care: Special Education and Community Rehabilitation in Low Income Countries, Captus Press, North York, 1996, p. 104Google Scholar.

32 Institute of Public Policy Research, Equal Rights for Disabled People, London, 1991, p. 104.

33 Ad Hoc Committee on a Comprehensive and Integral International Convention on the Protection and Promotion of the Rights and Dignity of Persons with Disabilities, “Letter Dated 7 October 2005 from the Chairman to All Members of the Committee”, UN Doc. A/AC.265/2006/1, 14 October 2005.

34 R. de Asís Roig, above note 30, p. 62.

35 The present list is not exhaustive. See also Geneva Convention (III) relative to the Treatment of Prisoners of War of 12 August 1949, 75 UNTS 135 (entered into force 21 October 1950) (GC III), Art. 110; Geneva Convention (IV) relative to the Protection of Civilian Persons in Time of War of 12 August 1949, 75 UNTS 287 (entered into force 21 October 1950) (GC IV), Arts 16, 21, 22, 27, 127. These articles reflect the same disability terminology as “invalid”, “sick”, “blind”, “mutilated” and “disfigured”.

36 GC IV, Art. 16 (emphasis added).

37 Ibid., Art. 17 (emphasis added).

38 Protocol Additional (I) to the Geneva Conventions of 12 August 1949, and relating to the Protection of Victims of International Armed Conflicts, 1125 UNTS 3, 8 June 1977 (entered into force 7 December 1978) (AP I), Art. 8(a) (emphasis added).

39 Mugabi, Ivan, “An Analysis of the Adequacy of Protection afforded by the Convention on the Rights of Persons with Disabilities (CRPD) in Situations of Armed Conflict”, Societies, Vol. 8, No. 2, 2018, p. 8CrossRefGoogle Scholar.

40 Ibid., p. 9.

41 This is defined in Articles 2, 5 and 9 of the CRPD, which address topics such as accessibility and measures against discrimination on the basis of disability.

42 See common Article 3; GC III, Art. 16; GC IV, Art. 13; AP I, Art. 75(1); Protocol Additional (II) to the Geneva Conventions of 12 August 1949, and relating to the Protection of Victims of Non-International Armed Conflicts, 1125 UNTS 609, 8 June 1977 (entered into force 7 December 1978) (AP II), Art. 4(1); Jean-Marie Henckaerts and Louise Doswald-Beck (eds), Customary International Humanitarian Law, Vol. 1: Rules, Cambridge University Press, Cambridge, 2005 (ICRC Customary Law Study), Rule 87, available at: https://ihl-databases.icrc.org/customary-ihl/eng/docs/v1.

43 The use of solitary confinement can result in inmates experiencing hallucinations, dementia and other mental disorders. See P. Scharff, “Solitary Confinement: History, Practice, and Human Rights Standards”, above note 3, p. 3; Report of the Special Rapporteur on Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment, Juan E. Méndez: Observations on Communications Transmitted to Governments and Replies Received, UN Doc. A/HRC/28/68/Add.1, 5 March 2015, para. 16; Report of the Special Rapporteur on Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment, UN Doc. A/66/268, 5 August 2011.

44 The use of solitary confinement for persons deprived of liberty with mental or psychosocial disabilities can cause severe psychological and physical effects, and often results in an aggravation of an existing mental condition. Shalev, Sharon, A Sourcebook on Solitary Confinement, Mannheim Centre for Criminology, London, 2008, p. 10Google Scholar; ACLU, Abuse of the Human Rights of Prisoners in the United States: Solitary Confinement, 2011; Metzner, Jeffrey L. and Fellner, Jamie, “Solitary Confinement and Mental Illness in U.S. Prisons: A Challenge for Medical Ethics”, Journal of the American Academy of Psychiatry and the Law, Vol. 38, No. 1, 2010Google ScholarPubMed; Kupers, Terry, “Waiting Alone to Die”, in Toch, Hans, Acker, James R. and Bonventre, Vincent Martin (eds), Living on Death Row: The Psychology of Waiting to Die, American Psychological Association, 2018, p. 56Google Scholar. Since the use of isolation for people with disabilities is very restrictive and may cause serious health effects, it amounts to cruel, inhuman or degrading treatment or punishment, and in some cases, it may constitute an act of torture.

45 GC III, Art. 30(1) (emphasis added).

46 Inter-American Court of Human Rights (IACtHR), Gonzáles et al. (“Cotton Field”) v. Mexico, Preliminary Objection, Merits, Reparations and Costs, Series C, No. 205, 16 November 2009, para. 43.

47 Vienna Convention on the Law of Treaties, 23 May 1969 (entered into force 27 January 1980) (VCLT), Art. 31.

48 The preparatory works can be used to confirm the meaning resulting from the interpretation carried out in accordance with the methods indicated in Article 31 of the VCLT, insofar as they allow us to verify whether the interpretation made with respect to a specific norm or term is consistent with the meaning of other provisions. Cf. IACtHR, Ownership of Rights of Legal Persons in the Inter-American Human Rights System, Advisory Opinion OC-22/16, Series A, No. 22, 26 February 2016, para. 45.

49 Geneva Convention relative to the Treatment of Prisoners of War, 118 LNTS 343, 27 July 1929 (entered into force 19 June 1931) (1929 PoW Convention).

50 Article 14 states: “Each camp shall possess an infirmary, where prisoners of war shall receive attention of any kind of which they may be in need. If necessary, isolation establishments shall be reserved for patients suffering from infectious and contagious diseases. The expenses of treatment, including those of temporary remedial apparatus, shall be borne by the detaining Power.”

51 ICRC, Report on the Work of the Conference of Government Experts for the Study of the Conventions for the Protection of War Victims, Geneva,14–26 April 1947.

52 See Final Record of the Diplomatic Conference of Geneva of 1949, Vol. 1, Section A, Federal Political Department, Berne, 1949.

53 GC III, Art. 30 (emphasis added).

54 Jean Pictet (ed.), Commentary on the Geneva Conventions of 12 August 1949, Vol. 3: Geneva Convention relative to the Treatment of Prisoners of War, ICRC, Geneva, 1960.

55 Ibid., p. 210.

56 Garay, Lucía Martinez, “The Uncertainty of the Predictions of Dangerousness: Consequences for the Dogmatics of Security Measures”, Indret: Revista para el análisis del derecho, No. 2, 2014, p. 8Google Scholar.

57 ICRC, Commentary on the Third Geneva Convention: Convention (III) relative to the Treatment of Prisoners of War, Geneva, 2020 (2020 Commentary on GC III), para. 2241, available at: https://ihl-databases.icrc.org/ihl/full/GCIII-commentary.

58 Ibid., para. 2242.

59 Ibid., para. 2244.

60 Ibid., para. 2256.

61 Ibid., para. 2239.

62 Ibid., para. 2260.

63 International Court of Justice (ICJ), Case Concerning the Territorial Dispute (Libyan Arab Jamahiriya/Chad), Judgment, ICJ Reports 1994, p. 22; IACtHR, The Word “Laws” in Article 30 of the American Convention on Human Rights, Advisory Opinion OC-6/86, 9 May 1986, para. 13; IACtHR, “Other Treaties” Subject to the Consultative Jurisdiction of the Court (Art. 64 American Convention on Human Rights), Advisory Opinion OC-1/82, 24 September 1982, para. 33.

64 Cecilia Medina and Claudio Nash, Manual de derecho internacional de los derechos humanos, Centro de Documentación, Defensoría Penal Pública, Santiago de Chile, 2003, p. 22; Mónica Pinto, “El principio pro homine: Criterios de hermenéutica y pautas para la regulación de los derechos humanos”, in Martin Abregú and Christian Courtis (eds), La aplicación de los tratados sobre derechos humanos por los tribunales locales, Editores del Puerto, Buenos Aires, 2004, p. 163. For a deeper insight into the criteria, see ICCPR, Art. 5; CEDAW, Art. 23; CRC, Art. 41; American Convention on Human Rights, Art. 29(b); European Court of Human Rights (ECtHR), Loizidou v. Turkey, Judgment, Series A, No. 310, 23 March 1995, para. 72; Zlata De Clément, “La complejidad del principio pro homine”, Revista Doctrina, No. 12, 2015, p. 103.

65 C. Medina and C. Nash, above note 64, p. 22. See ECtHR, Soering v. The United Kingdom, Appl. No. 14038/88, Judgment, 7 July 1989, para. 87; ECtHR, Dudgeon v. The United Kingdom, Appl. No. 7525/76, Judgment, 27 October 1981; IACtHR, The Interpretation of the American Declaration of the Rights and Duties of Man in the Framework of Article 64 of the American Convention on Human Rights, Advisory Opinion 10/89, 14 July 1989, para. 37; IACtHR, Gender Identity, and Equality and Non-Discrimination for Same Sex Couples, Advisory Opinion 24/17, 24 November 2017, para. 59.

66 VCLT, Art. 31. See IACtHR, Advisory Opinion OC-1/82, above note 63, para. 33; ICJ, Territorial Dispute, above note 63, p. 22.

67 Geneva Convention (I) for the Amelioration of the Condition of the Wounded and Sick in Armed Forces in the Field of 12 August 1949, 75 UNTS 31 (entered into force 21 October 1950) (GC I); ICRC, Commentary on the First Geneva Convention: Convention (I) for the Amelioration of the Condition of the Wounded and Sick in Armed Forces in the Field, Geneva, 2016 (2016 Commentary on GC I).

68 GC I, Art. 12(1); Geneva Convention (II) for the Amelioration of the Condition of Wounded, Sick and Shipwrecked Members of Armed Forces at Sea of 12 August 1949, 75 UNTS 85 (entered into force 21 October 1950) (GC II), Art. 12(1); GC III, Art. 13(1); GC IV, Arts 5, 27; AP I, Art. 75(1); AP II, Art. 4(1); ICRC Customary Law Study, above note 42, Rules 87, 88.

69 2016 Commentary on GC I, above note 67, para. 553.

70 See also 1899 and 1907Hague Regulations, Art. 4; Geneva Convention on the Wounded and Sick, 1929, Art. 1; 1929 PoW Convention, Art. 2. Today, see in particular GC I, Art. 12; GC II, Art. 12; GC III, Art. 13; GC IV, Art. 27; AP I, Arts 10, 75. For IACs, the principle of humane treatment was codified in the Hague Regulations of 1899 and 1907, the Geneva Conventions of 1949, and AP II.

71 ICJ, Military and Paramilitary Activities in and against Nicaragua (Nicaragua v. United States of America), Judgment, ICJ Reports 1986, paras 218–219.

72 UN, Compilation of General Comments and General Recommendations Adopted by Human Rights Treaty Bodies, UN Doc. HRI/GEN/1/Rev.7, 12 May 2004, paras 176–178.

73 2016 Commentary on GC I, above note 67, para. 321.

74 See ECtHR, Salgueiro da Silva Mouta v. Portugal, Appl. No. 33290/96, 21 December 1999.

75 To date the CRPD has 184 States Parties, making it one of the most widely ratified human rights treaties.

76 Alice Priddy, Disability and Armed Conflict, Geneva Academy Briefing No. 14, 2019, p. 55.

77 Ibid., p. 55.

78 2020 Commentary on GC III, above note 57, para. 572.

79 Minkowitz, Tina, “The United Nations Convention on the Rights of Persons with Disabilities and the Right to Be Free from Nonconsensual Interventions”, Syracuse Journal of International Law and Commerce, Vol. 34, No. 2, 2007, p. 412Google Scholar.

80 IACtHR, Compulsory Membership in an Association Prescribed by Law for the Practice of Journalism (Arts. 13 and 29 American Convention on Human Rights), Advisory Opinion OC-5/85,13 November 1985, para. 52. See also IACtHR, Loayza Tamayo v. Peru, Judgment, 17 September 1997, para. 44; ECtHR, Loizidou, above note 64, para. 72.

81 Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment, UN Doc. A/RES/39/46, 10 December 1984 (entered into force 26 June 1987), Art. 1.

82 ICTY, The Prosecutor v. Zejnil Delalic et al., Case No. IT-96-21-T, Judgment, 16 November 1998, para. 111.

83 ICTY, The Prosecutor v. Dusko Tadić, Case No. IT-94-1-A. Judgment, 15 July 1999, para. 723.

84 ICTY, Delalic, above note 82, para. 551.

85 The term “cruel, inhuman or degrading treatment or punishment” captures acts which are legally and morally reprehensible but fall short of the specific crime of torture. See Nowak, Manfred and Janik, Ralph R. A., “Torture, Cruel, Inhuman or Degrading Treatment or Punishment”, in Clapham, Andrew, Gaeta, Paola and Sassòli, Marco (eds), The 1949 Geneva Conventions: A Commentary, Oxford University Press, Oxford, 2015, pp. 317–342Google Scholar.

86 ICRC, “What is the Definition of Torture and Ill Treatment?”, Geneva, 15 February 2005, available at: www.icrc.org/en/doc/resources/documents/faq/69mjxc.htm.

87 It should be noted that to date there is no international standard for the use of restraint to restrict the right to liberty of persons with mental disabilities, but in any case, any restraint must be very specific and short. Thus, we agree with Renato Constantino's idea that “this action would only consist of the limitation of locomotor freedom in a reduced space”. See Renato Antonio Constantino Caycho, “¿Hogar, dulce hogar? La privación de libertad de personas con discapacidad en casa particulares a partir de la sentencia Guillén Domínguez del tribunal constitucional peruano”, Pontifical Catholic University of Peru, available at: https://tinyurl.com/yckhdfsr.

88 GC III, Part IV; ICRC Customary Law Study, above note 42, Rule 128.

89 A. Priddy, above note 76, p. 72.

90 Rafael de Asís, “Lo razonable en el concepto de ajuste razonable”, in E. Salmón and R. Bregaglio (eds), above note 26, p. 104.

91 Committee on the Rights of Persons with Disabilities, General Comment No. 2, “Article 9: Accessibility”, UN Doc. CRPD/C/GC/2, 22 May 2014, para. 1.

92 Renata Bregaglio, “El principio de no discriminación por motivo de discapacidad”, in E. Salmón and R. Bregaglio (eds), above note 26, p. 91.

93 Ibid., p. 93.

94 Marcial Rubio Correa, Francisco Eguiguren Praeli and Enrique Bernales Ballesteros, Los derechos fundamentales en la jurisprudencia del Tribunal Constitucional: Análisis de los artículos 1,2 y 3 de la Constitución, 1st ed., Fondo Editorial de la PUCP, Lima, 2011, p. 146.

95 R. de Asís, above note 91, p. 105.

96 R. Bregaglio, above note 92, pp. 94–95.

97 Robert Alexy, Teoría de los derechos fundamentales, trans. Ernesto Garzón Valdés, Centro de Estudios Constitucionales, Madrid, 1997, p. 100.

98 R. de Asís, above note 90, p. 113.

99 GC III, Art. 14; 2020 Commentary on GC III, above note 57, para. 1658.

100 GC III, Art. 16; AP I, Arts 9(1), 75(1). See also ICRC Customary Law Study, above note 42, Rule 88.