It could technically be classified as "elective," depending on how insurance companies and hospitals want to legally phrase it. Because Daonnachd is on medication (Abilify, I think?), the hospital could argue that his medication is his main form of treatment and that ECT is merely a "supplement" to that treatment, even though it's the other way around. When you call it a "supplement," it makes it sound like it's not necessary.

It's more about hospitals and insurance companies coming up with BS reasons to not do it than it is about whether ECT is "elective" or not.