The form must be witnessed by two people, eighteen years of age or older, who are not the health care agent or the alternate agent that you list. Do not sign the main signature section (section 5) or the organ donation section (if you choose to fill it out) unless you are in the presence of your witnesses.
After you sign the form, the witnesses must sign and write their addresses. The witnesses’ signatures attest that you were of sound mind and acting upon your own free will at the time you signed the form. If you are unable to sign the form yourself (for example, if you have limited movement in your hand or arm) you may ask someone else to sign for you. In this case, this person must sign in the presence of you and your witnesses.
If you have a condition that has led you to have periods where you have lost capacity to make your own decisions, or may lead you to lose capacity, it may be worth asking a neurologist or mental health professional to sign as one of the witnesses. As they are able to make a professional assessment, their attestation that you were of sound mind at the time the form was completed may be valuable if there is ever any question of your cognitive state when you signed the form.