It's definitely not a certainty, but the odds are against us, from whatever I've read and been told (and experienced).

But, you know, despite that, life is rare and beauutiful, and we are currently living in a momentous phase in human society. There is joy and wonder wherever we look, and, as long as we seek treatment, I strongly believe we'll be able to able to live with depression.

Everyone has something. Some are depressed, some are diabetic, some are in wheelchairs. Everyone has some lifelong problem. We are all fighters. We should be proud of ourselves, and stubbornly refuse to let life wear us down.