Money won't cure illness or solve personalilty issues...but it will solve monetary issues like debt, making ends meet, etc.
And if you have enough money to take away the worry of making ends meet, meeting your bills, keeping you car running, then your stress level is bound to be less, making it easier to relax and enjoy life a little. It would cut tensions between married partners that are stressing because of finances.
But, even the money alone won't solve anything. One would have to be self-discliplined to spend it wisely and not go off on some fools errand, wasting it all.
I'ld like to volunteer for a study on the impact of sudden riches on the financially struggling if anyone is interested in funding such a study.