A/HRC/20/24 or other forms of custody; and that they are not detained, charged or prosecuted for the illegality of their entry or residence or for their involvement in unlawful activities which are a direct consequence of their situation as trafficked persons. The Special Rapporteur on trafficking in persons, especially women and children, has also stated that trafficked persons should not be detained, charged or prosecuted for the illegality of their entry into or residence in countries of transit and destination (see A/64/290). (d) Vulnerable categories of migrants 43. Detention can be particularly damaging to vulnerable categories of migrants, including victims of torture, unaccompanied older persons, persons with a mental or physical disability, and persons living with HIV/AIDS. The UNHCR guidelines provide that, given the very negative effects of detention on the psychological well-being of those detained, active consideration of possible alternatives should precede any order to detain asylum-seekers belonging to vulnerable categories. The Special Rapporteur is of the opinion that the same principle should apply to vulnerable migrants. In the event that individuals falling within these categories are detained, it is advisable that this should only be on the certification of a qualified medical practitioner that detention will not adversely affect their health and well-being. In addition, there must be regular follow up and support by skilled personnel. They must also have access to adequate health services, medication and counselling. 44. Victims of torture are already psychologically vulnerable due to the trauma they have experienced and detention of victims of torture may in itself amount to inhuman and degrading treatment. 45. The Special Rapporteur has received information indicating that the detention of persons who suffer from mental illness is quite frequent in migrant detention centres, which lack resources to provide them with the required medical attention. The Standard Minimum Rules for the Treatment of Prisoners provide that persons who suffer from mental illnesses shall be observed and treated in specialized institutions under medical management. 46. Research shows that immigration detention has widespread and seriously damaging effects on the mental (and sometimes physical) health of detainees. For those with preexisting mental illness, serious consideration must be given to alternatives to detention or other arrangements that meet their treatment needs, ensuring their protection from cruel, inhuman or degrading treatment or punishment, and the right to humane conditions of detention. Furthermore, mental health issues may sometimes be caused, at least partly, by detention. In communication No. 900/1999, the Human Rights Committee held that the continued detention of a migrant when the State was aware of his mental condition and failed to take the steps necessary to ameliorate his mental deterioration constituted a violation of his rights under article 7 of the Covenant (the prohibition of torture and cruel, inhuman or degrading treatment or punishment) (para. 8.4). It further considered that “deportation of the author to a country where it is unlikely that he would receive the treatment necessary for the illness caused, in whole or in part, because of the State party‟s violation of the author‟s rights would amount to a violation of article 7 of the Covenant” (para. 8.5). (e) Stateless persons 47. Stateless persons do not benefit from the consular or diplomatic protection of a State, often do not possess identity documents and do not have a country to which to be returned. Stateless persons are especially vulnerable to prolonged detention. Being stateless and therefore not having a country to which automatic claim might be made for the issue of a travel document should not lead to indefinite detention, and statelessness cannot be a bar 12