No person who is under guardianship or treatment or confinement by virtue of being a mental incompetent, or who has been adjudicated or is under treatment or confinement as a drug addict, shall purchase, own, carry, transport, or have in his or her possession or under his or her control any firearm. Any person affected by the provisions of this section, other than a person who has been pronounced criminally insane by competent medical authority, after the lapse of a period of five (5) years from the date of being pronounced cured by competent medical authority, may, upon presentation of an affidavit issued by competent medical authority to the effect that he or she is a mentally stable person and a proper person to possess firearms, make application for the purchase of the firearm(s). Any person affected by the provisions of this section, in making application for the purchase of firearms and in executing the application, voluntarily waives his or her right to refuse or refrain from disclosing any confidential information, including, but not limited to, any information arising from the physician-patient relationship, pertinent to a determination by the proper authorities regarding the approval or disapproval of this application. Any person affected by the provisions of this section, in making application for the purchase of firearms and in executing the application, further agrees to allow the proper authorities to investigate any and all medical records of the applicant pertinent to a determination by the authorities regarding the approval or disapproval of this application. In the event that the application is approved, and if the person has no other disqualifying record, he or she will be allowed to purchase and possess firearms.