Sure they can. Once physicians have accepted the notion that killing a patient can be a form of treatment, the rest is just a matter of degree.
“The response rate was 64% (n=1456). Most physicians found it conceivable that they would grant a request for EAS in a patient with cancer or another physical disease (85% and 82%). Less than half of the physicians found this conceivable in patients with psychiatric disease (34%), early-stage dementia (40%), advanced dementia (29–33%) or tired of living (27%). General practitioners were most likely to find it conceivable that they would perform EAS.”