The will made by mental patients is generally invalid, but if they are intermittent mental patients, the will is valid when they are mentally normal and invalid when they are ill; However, the will made by adults who have been cured of mental illness is valid, and the will made by people who have been diagnosed with Alzheimer's disease and are old and unconscious is invalid.

The effective conditions of the agent's will:

A valid will written by an agent must meet the following conditions:

1. The testator dictated the contents of the will, and the witness wrote the will instead of the testator. A will for a book substitute is not a will made by the book substitute according to his own wishes, but a will recorded by the book substitute truthfully according to the will of the testator, and the contents of the will cannot be changed or modified;

2. There must be more than two witnesses to witness the agent's will, one of whom can act as an agent. Witnesses are generally citizens designated by the testator and agreed by him, and cannot be witnesses in the name of the organization;

3. The agent, witness and testator must sign the will and indicate the year, month and day. The testator shall submit the written will to other witnesses for verification and read it to the testator on the spot. After the testator finds it correct, it shall be signed by the testator, other witnesses and the testator, and the specific date shall be indicated;

4. The testator shall have full capacity for civil conduct, and shall not be a minor or mentally or intellectually unsound person. The testator shall not be an heir or legatee, nor shall he be a person interested in the heir.

Legal basis:

People's Republic of China (PRC) Civil Code

Article 133 A natural person may make a will and dispose of his personal property in accordance with the provisions of this Law, and may designate an executor. A natural person may make a will to designate personal property to be inherited by one or more legal heirs. A natural person may make a will to donate personal property to an organization or individual other than the state, the collective or the legal heir. A natural person may establish a testamentary trust according to law.

Article 142 A testator may withdraw or change his will. After making a will, if the testator carries out a civil legal act that is contrary to the contents of the will, it shall be regarded as withdrawing the relevant contents of the will. There are several wills. In case of conflict, the last will shall prevail.

Article 143 A will made by a person without or with limited capacity for civil conduct is invalid. A will must express the true meaning of the testator, and a will made by fraud or coercion is invalid. Forged wills are invalid. If the will is tampered with, the tampered contents are invalid.