Illinois Severe Mental Illness Information, Laws, & Helpful Resources

405 ILL. COMP. STAT. 5/3-600. A person 18 years of age or older who is subject to involuntary admission on an inpatient basis and in need of immediate hospitalization may be admitted to a mental health facility pursuant to this Article.

405 ILL. COMP. STAT. 5/3-701(a). Any person 18 years of age or older may execute a petition asserting that another person is subject to involuntary admission on an inpatient basis. 405 ILL. COMP. STAT. 5/1-119. "Person subject to involuntary admission on an inpatient basis" means: (1) A person with mental illness who because of his or her illness is reasonably expected, unless treated on an inpatient basis, to engage in conduct placing such person or another in physical harm or in reasonable expectation of being physically harmed; (2) A person with mental illness who because of his or her illness is unable to provide for his or her basic physical needs so as to guard himself or herself from serious harm without the assistance of family or others, unless treated on an inpatient basis; or (3) A person with mental illness who (i) refuses treatment or is not adhering adequately to prescribed treatment; (ii) because of the nature of his or her illness, is unable to understand his or her need for treatment; and (iii) if not treated on an inpatient basis, is reasonably expected, based on his or her behavioral history, to suffer mental or emotional deterioration and is reasonably expected, after such deterioration, to meet the criteria of either paragraph (1) or paragraph (2) of this Section. In determining whether a person meets the criteria specified in paragraph (1) or (2), or (3), the court may consider evidence of the person's repeated past pattern of specific behavior and actions related to the person's illness.

405 ILL. COMP. STAT. 5/3-751(a). Any person 18 years of age or older may execute a petition asserting that another person is subject to involuntary admission on an outpatient basis. 405 ILL. COMP. STAT. 5/1-119.1. "Person subject to involuntary admission on an outpatient basis" means: (1) A person who would meet the criteria for admission on an inpatient basis as specified in Section 1119 in the absence of treatment on an outpatient basis and for whom treatment on an outpatient basis can only be reasonably ensured by a court order mandating such treatment; or (2) A person with a mental illness which, if left untreated, is reasonably expected to result in an increase in the symptoms caused by the illness to the point that the person would meet the criteria for commitment under Section 1119, and whose mental illness has, on more than one occasion in the past, caused that person to refuse needed and appropriate mental health services in the community.