Is a patient with Alzheimer treated as a diseased or an insane?

In the Name of Allah, The All-Merciful, The Ever-Merciful.

Praise be to Allah; Prayers and Peace of Allah be upon the Messenger, his household and his companions.

An Alzheimer patient loses his mind occasionally; hence he has the ruling of the one with intermittent insanity. He is competent and charged when he is in the state of normal memory and awareness and is incompetent otherwise. For court-related issues, one has to consult experts. As to how his family should treat him, the precedence should be to excusing and forgiving him since they lack an expert-eye to identify his status.

And Allah knows best.