I would venture to say this is just a sign of the times. The weight of the world is upon us all. Some people simply can't handle the stress and complexity of day-to-day modern life. Hell, I've been feeling COMPLETELY overwhelmed myself lately.
All the more reason to stop, take a deep breath and crack open your favorite brew, and force yourself to relax.
Life is hard, complex, tiring, annoying, stressful, painful and downright confusing sometimes. But if you aren't feeling that way at least half the time, they you aren't living at all!
Just remember the good times you've had, make plans to have some more, and don't forget to stop and appreciate the small things along the way!
It sounds dumb, but every time I look at my puppy's eyes, I know she needs me and depends on me to take care of her, and she is just a simple little creature who wants nothing but food, a nice long nature walk now and again, and a snuggly warm place to sleep. And that's all there is to life really!

Bart