Who writes Facebook ads?

Obviously the title of this post is a rhetorical question.

In fact I wrote a handful of Facebook ads myself just last week.

But what I want to know is who writes ads like the one above.

Depression is a serious issue.

And I very much doubt a sufferer would benefit from clicking on a Facebook ad to join a clinical trial.

A clinical trial for what? And with whom?

I'd like to hope Facebook monitor this sort of stuff.

But somehow I doubt it...