His positive outlook on life has made Parkinson's sufferer Michael J Fox an inspiration to many. And it brings a special resonance to his latest TV project – a personal investigation into the nature of optimism.
Michael J Fox: Adventures Of An Incurable Optimist - which airs in North America in May - is a one-hour special following the semi-retired actor and father-of-four as he travels the world in search of what makes people happy.
In the programme the 47-year-old Back To The Future star explores science and looks to his own personal experiences. Among the places he visits is the Himalayan country of Bhutan, which in 2006 earned the title of the world's eighth happiest nation.