A suicidal person is not of sound mind.
Also, why would someone's academic qualifications entitle them to essentially sentence a suicidal person to death?
[1]: e.g "Also, if by some chance a psychiatrist doesn’t give a patient Adderall, that patient practically always goes to another psychiatrist, and that next psychiatrist does." (https://slatestarcodex.com/2017/12/28/adderall-risks-much-mo...)
Your argument goes both ways then, both for those who are pro-euthanasia and those who completely are against it.