I am happy when internal factors such as neuronal balance etc. take place.
I tend to think things could be much much worse and am very thankful for the good things that life has brought along so far. However I tend to get down when I think about the sense of life and when I am invaded by pessimism, which happens regularly.
As for happiness through possessions, by pure geographical luck I belong to the group beyond the whatever-dollar-mark which can afford realizing that material things are not the guarantee for happiness. Not that I am an idealist who thinks there is no difference between being poor and being rich. The kind of medical treatment you get, for example, is very different. But of course you needn't be a millionaire to get most good things in life (unless you are an unsatiable addict to money, in which case you have a serious psychological problem
So, I would not say that money or material possessions are in any way one of the cause of my down moments.