The court shall cause notice of a petition and of the time and place of any hearings under this chapter to be given to the respondent; the respondent’s parents, if a minor; the respondent’s attorney; the petitioner; the state‘s attorney; the superintendent or the director of any hospital or treatment facility in which the respondent is hospitalized or is being treated; the spouse of the respondent, if the spouse’s whereabouts is known; the guardian, if any, of the respondent; and such other relatives or persons as the court may determine. The notice must be given at the earliest possible time and sufficiently in advance of the hearing date to permit preparation for the hearing.