RunintheCity saidOh for god's sake. That's ridiculous. Old people get depressed because they're close to death and they know it!
My old upstairs neighbor, a fantastically vibrant gay man in his 70s until a series of strokes robbed him of his vigor, lived alone and enjoyed it. He'd lived a pretty wild life in his youth 18-40, then settled into a couple of long term relationships. Once his last lover passed, he sold his house, moved into his apartment, but led a full life he enjoyed. A life full of friends, travel, dinners, social outings, etc, although by the time I was his neighbor he'd scaled back his socializing, largely because he was still working and preferred to just go to dinner and come home thereafter.
He only admitted to any sort of apprehension/depression/sadness when he would have occasion to contemplate his advancing age. After the first stroke, which resulted in minor physical setbacks, he maintained most of his spirit and regained a lot of his physical well-being. Subsequent strokes have worsened his overall health, but he still has his spunk.
I didn't say the initial comment in a dismissive manner. It's just the truth. Once we hit a certain age and are constantly cognizant of our looming demise, if we focus on it of course we are going to get depressed. But my old neighbor is an example of how, even when your circumstances are tough, you don't have to give in to that.