Serious Mental Illness: A condition of persons who are eighteen years of age or older and who, as a result of a mental disorder as defined in A.R.S. § 36-501, exhibit emotional or behavioral functioning which is so impaired as to interfere substantially with their capacity to remain in the community without supportive treatment or services of a long -term or indefinite duration. In these persons mental disability is severe and persistent, resulting in a long-term limitation of their functional capacities for primary activities of daily living such as interpersonal relationships, homemaking, self-care, employment and recreation..