For many people, what you say rings true, but it's dangerous to imply that that these feelings are purely a product of someone's thinking and that they can fix them on their own. There are people who, no matter how much they sit down and think things through, try and sort out their problems, etc, are going to feeling depressed -- likely due to chemical imbalances and structural differences in the brain. Thinking about suicide might be how this manifests.

Telling someone they can think themselves or "figure themselves out" to not being homosexual, schizophrenic or transgender seems crazy to many people, but not crazy when we say the same about depression. Pushing "think about it more! sort our your life!" as The Solution can be dangerous in the case where deferring more radical treatment is necessary or prudent, and the mentality that "I can think/will my way out of this" is a frequent excuse or cause for noncompliance with medication in some patients who actually do need it to not be a danger to themselves, or others.

I'm not implying the poster is such a case, or that such treatment shouldn't be tried, but it can and will fail in certain cases, and it's easy for others and the patient to justify "well I just need to try harder" or to push blame when that's deferring necessary treatment.

"There are people who, no matter how much they sit down and think things through, try and sort out their problems, etc, are going to feeling depressed"

Although you're probably right, it's also dangerous to promote that viewpoint. A depressed person accepting themselves as inevitably and irreversibly depressed is not productive, even if that's the case. It's not analogous to being gay where you can accept it and live a happy life.

I suppose accepting that you're permanently depressed could help you cope with it, but I'd be scared of having people assume thats the case before exhausting all other options.

You're wrong about not being able to live happily ever after: It's never accepting you'll be forever unhappy -- it's accepting you can't be without aid or intervention (e.g. medication, therapy, etc). I never stated that they're doomed to feel depressed, just that they're doomed to feel depressed if they don't do something other than sit and think. Depression tends to lead to a lot of rumination anyways, so it probably will seem pretty ridiculous to them to be told to be more introspective.

To clarify, I put those (schizophrenia, homosexuality, transgender) as examples of brain structure and wiring (just like clinical depression) and mentioned homosexuality explicitly because it seems less stigmatized than mental illness currently. A gay person can accept being gay and live a happy life, but they can't think themselves into being straight if they try hard enough. An individual diagnosed with major depressive disorder can accept they are clinically depressed and require treatment, then take the treatment and live a happy life, but they can't think themselves into not requiring outside aid to be in a non-depressed state. Society is a lot more accepting of the gay person than the depressed one though.

I didn't mean to imply that it can just be fixed by the person working on their own, rather that you need to face the depression itself rather than go down the road of trying other, outside, things in an attempt to indirectly fix the feelings themselves.

Of course medication/therapy/even acceptance of a chemical imbalance are not off the table at all.

A big problem with depression is that it makes you feel very guilty, unnecessarily, so I really want to make clear that I didn't want to imply somebody should feel that it's somehow their fault at all.

In many ways a large part of it is getting outside help. I really do recommend that, and have found that extremely helpful myself.