Came across this nice advert (look at me trying to sound all British and fancy) at JFK yesterday:
I think it has a good message, but makes a shaky comparison. At the bottom, it asks "So why do some say that about depression?"
Clearly, one can not just "get over" depression. It's a devastating illness, and it's silly and counterproductive to blame someone for being depressed, or to pretend there's a magic button they can press to turn it off.
On the other hand, there is an important difference between cancer and depression: there exist purely mental (e.g., mindfulness-based) therapies that have a large impact on the latter, but the mind seems to have almost no ability to affect the former (other than with acceptance).
The argument that "the mind is just the brain" (i.e., just a physical device made of neurons and neurotransmitters) doesn't help even if it turns out to be true, because our whole model of moral responsibility is based on the idea that we still have some say in the matter (even if the "we" is physical).
So the message to not blame those with mental disorders is a great one. But it's important not to swing the other way and suggest that we have little or no mental power over own recovery. That can be disempowering in a subtle but powerful way.
(For a stronger argument, just see studies where manipulating a subject's belief in the existence of free will affects how hard they try to accomplish the given task. This should be something even reductive materialists can sink their teeth into.)