These soundbite-style phrases are a convenient way to get a message across, but for those who are far down the path they are just words in my opinion. Back in the 80s in the United States Nancy Reagan led her "Just Say No" campaign to get kids to avoid drugs. Drugs coupled with peer pressure can be incredibly hard to resist and it takes more than a few words to sway kids.
A couple years ago we had the "It Gets Better" campaign to stop suicide among gay teens. I do agree that as an older gay man I did eventually gain a sense of self worth, that I wasn't bad or inferior solely because of my sexual orientation. However, speaking of suicide in general, no, sometimes it does NOT get better. There are small changes we can make in our lives, but I equate the larger driving factors to a sleeping giant: he's always inside me, sometimes sleeping, sometimes active, but always there and always will be.