Originally Posted by wally
A woman can have everything her heart desires: all the money in the world, a huge mansion in Hawaii, and a man that cherishes her and treats her like a queen, and there will still be something missing from her life.
First, I'll assume you're being ironic in this specific sentence. If you've been busy with trying to provide your women with a huge mansion in Hawaii, that may be the reason why they weren't happy

I mean, of course money can buy little satisfactions, but it hardly makes someone happy. I really think that being too focused on "stuff" is a good way for being unhappy.
I cannot know what would make your wife happier. I can say that there are lots of possibilities why she may be depressed.
Maybe she had lived her youth dreaming too much of her future, or thinking too much about a "perfect life" that turned out not to be the real future coming?
Maybe she doesn't feel fully realized or she would like to have a different job?
Maybe she's finding it hard to build the kind of family she really wants?
Maybe she's just feeling frightened for watching youth slip away, and her lifestyle with it?
You might have just met a series of women who had different reasons to be sad, don't automatically assume that it happens to all women because that's far from truth. I do feel like women are more prone to depression, and while this might even have a physiological explanation (which I cannot give), I rather think it's because the world cultures always tend to give women less opportunities than men, and often make women more dependent of men.
Perhaps you could ask yourself this. Are you always making women too much dependent on you? Did your girlfriends have their own job, money, friends, time alone etc. to do what they wanted or do you think you may kind-of "monopolize" their life too much? Just wandering...
Originally Posted by wally
Literally every woman I've ever known has been on, is currently on, or has thought about going on some sort of medication - anti-depressant, mood stabilizer, etc. - to make up for the fact that they are simply not capable of being happy.
Incidentally, it is sad to hear that in the US it is so common to "cure" depression by chemicals as the first resort. It doesn't sound a good idea to me on a long-term perspective.