In order for the DNR to be honored, the patient would have to be mentally stable/competent and be presented with information he can understand to make an informed decision about what he wants. Kind of similar to how a patient can’t be sedated prior to signing informed consent for a surgery. The questions I have about this case are:
Does the hospital perform a mental assessment on patients before allowing them to make changes to their advanced directives?
Does the hospital have policies/procedures for suicidal patients and whether that person's DNR is honored or dishonored?
Is there documentation showing the current advanced directives compared to the previous advanced directives? Were there any drastic changes in these advanced directives after his wife died? If so, what were the changes?
Is there a history of suicidal ideation or mental health treatment, and is it documented in the medical record? (documentation that notes his mental status before his wife died, compared to after)
Can the family attest to his behavior before his wife died compared to after; did they notice any drastic changes in his behavior? Was he trying to give away his personal belongings? Was he unusually happy/hopeful?
Is there a living will? A next of Kin?