Personally I think the reason that suicide is so prevalent today is for 2 main reasons:
1) People have taken religion so out of context over the past hundreds of years that today we get these very hard to live with versions that have little depth and practicality in our lives. So something that is supposed to "save you" is actually "killing you"
For example this whole idea of judgement day and sin, etc. I don't think people are buying it anymore. And besides most Christian religions teach that no matter what you do you will be forgiven (just have to spend more time in purgatory) and so people feel anything is better than living in confusion and without purpose and so they end their physical life here.
2) We live in a world of crazy demands (we did this to ourselves of course) and the ego has a lot to do with this. There is always this not enoughness, not enough friends, love, money, etc. So people just can't keep up with the rat race and they feel that sucide is the only way out.
There are of course isolated psychological cases, but in a direct or indirect way I still think it stems from either number one or two.