A person 18 years of age or older whose behavior indicates that he/she is mentally incapable of adequately caring for himself/herself and his/her interests without serious consequences to himself/herself or others, or who, because of physical or mental impairment, is unable to protect himself/herself from abuse, neglect, exploitation, sexual abuse, or emotional abuse by others, and who has no guardian, relative, or other appropriate person able, willing, and available to assume the kind and degree of protection and supervision required under the circumstances (Code of Alabama § 38-9-2(2) (1975)).