But what if finding happiness was easier than you thought? And could be achieved across all areas of your life?
Professor Paul Dolan argues that we can all be happy if we focus not on how we think, but how we act.
Author of new book Happiness By Design; Finding pleasure and purpose in everyday life (Allen Lane; £20) Paul shows us how happiness is a combination of the experiences of both pleasure and purpose over time, and depends on how we allocate our attention on various stimuli vying for it.
'Many books on happiness make prescriptions about what to do in order to be happier, without defining what happiness is in the first place,' Paul explains. 'But the pursuit of happiness requires a definition of just what is being pursued. Some activities we get pleasure from, like watching TV, are different from those that bring us purpose, such as work.
'The different ways we define happiness affect what we can do to improve it. So a clear definition should be, but rarely is, a fundamental concern for any book on happiness. Having worked at the interface of economics, psychology, philosophy, and policy for two decades, I think I am well placed to make a strong case for the following definition: happiness is experiences of pleasure and purpose over time.'
But how can we go about achieving happiness? Read on for Paul's advice...