Does that mean they are not persons?

Dr. John Dunlop writes about the importance of honoring dementia patients as God's image-bearers, which I fully affirm, but I think his point is valid for other areas. How do we see people and think about them? Are there certain qualities and categories that would cause us to treat them as less than fully human and less deserving of respect? In the quote below, Dunlop call this devastating and a tragic error. I agree.

In a day when there is much confusion as to what it means to be a person, the church must teach a robust view of personhood that is based on our being made in the image of God... if you asked what that really means, it's likely they would say something like, "Well, I guess that means they are like God, they are intelligent, can make their own choices, and have the ability to relate to others." If you probed further and asked, "Does that mean people with severe dementia, who are not intelligent, cannot make their own choices, and do not have the ability to relate to others, no longer reflect God's image?" They would likely look surprised, perhaps a bit uncomfortable, and say, "I'm not sure." If we pursued our pretend discussion one step further and asked, "Does that mean they are not persons?"... Just as I never recall hearing the word dementia in a sermon, I do not recall being taught in church that personhood is an ontological (something that is true by definition) state and that all those made in God's image are persons possessed with inherent dignity and worthy of respect we would give to the one whose image they bear.

Whether we are willing to face these difficult questions or not, we have to acknowledge that they are important, and the consequences of our taking the wrong view are devastating. The only way to prevent such tragic errors is for the church to make a priority of teaching that all humans are person made in the image of God and should therefore be treated with respect for the dignity they possess.

Finding Grace in the Face of Dementia, John Dunlop, M.D., Crossway, 2017, pg. 147.