The following words and phrases when used in this chapter shall have the meanings given to them in this section unless the context clearly indicates otherwise:

"Attending physician." A physician who has primary responsibility for the treatment and care of the declarant or principal.

"Declarant." An individual who makes a declaration in accordance with this chapter.

"Declaration." A writing made in accordance with this chapter that expresses a declarant's wishes and instructions for mental health care and mental health care directions and which may contain other specific directions.

"Mental health care." Any care, treatment, service or procedure to maintain, diagnose, treat or provide for mental health, including any medication program and therapeutical treatment.

"Mental health care agent." An individual designated by a principal in a mental health power of attorney.

"Mental health care provider." A person who is licensed, certified or otherwise authorized by the laws of this Commonwealth to administer or provide mental health care in the ordinary course of business or practice of a profession.

"Mental health power of attorney." A writing made by a principal designating an individual to make mental health care decisions for the principal.

"Mental health treatment professional." A licensed physician who has successfully completed a residency program in psychiatry or a person trained and licensed in social work, psychology or nursing who has a graduate degree and clinical experience in mental health.

"Principal." An individual who makes a mental health power of attorney in accordance with this chapter.