Money can't buy you happiness

Have you heard that saying that "Money Can't Buy You Happiness"? Is it true? Especially around this time of year when people go into a buying frenzy for that one day that can make or break relationships and reduce grown, sensible, balanced people to weeping, quivering shadows of their former selves (I am just SO positive aren't I today!).
I've been dipping into a report (Mental Capital and Wellbeing:Making the most of ourselves in the 21st century) presented to policy makers in government a few years ago compiled from opinions / input of 400 experts. I've read half of the Executive Summary so far which is very broad. I think mental capital is our mental/cognitive and emotional abilities and mental wellbeing refers to our ability to achieve and respond.
In the summary it's noted that debt is a stronger risk factor in mental disorder than low income. So for the debt ridden, money would buy happiness. This does not bode well for the nation as the recession continues and more people fall into debt.
Today the Tories have announced they are want to find a way to measure the happiness of the nation, arguing that we should not measure progress solely in terms of economic growth. In part, this sounds good since there has been too much emphasis on how rich or not we are in terms of money following the "Greed is Good" / Thatcherite philosophy. The fact that there will be an attempt to move away from just assessing our growth in terms of wealth/poverty to a more richer understanding of the growth of our culture and our abilities as a nation to address the challenges in the future is to be welcomed.
But this is a Tory government and I'm sceptical. I can't help but laugh at the comic potential of Government determining future policies by how happy they make us. Will they like overindulgent parents ensure that the policies don't lead to one mass tantrum and stomping of foot - making sure in a patronising way that we are happy, smiley people all day long. Will it be shown that the nation is much happier when they are injected with happy pills and that this will inform the NHS policies of the future - come in for your daily does of the happy drug you little nation you. Is it going to unearth who among us is Ebenezer Scrooge and who is Bob Crachit (though in that story, ES gives money to BC and oh gosh we are back to economic measures of happiness)?
Unlike economic wealth, happiness is partly subjective. Yes you can measure seratonin levels but it's also a feeling which is a consequence of our past experiences which determines how we react to events. One person can become incredibly happy at the sight of a beautiful flower whereas another fails to see the beauty and so doesn't react in the same way. What do you think - what measure of happiness is valid to you?