Prozac is the most prescribed anti-depressant in America and psychologist Jim Goodwin wants people to know all about the "wonder" drug he is on a mission to promote as a panacea for depression. The human-interest series travels to Wenatchee, Washington - known as Happy Valley because of the large numbers taking the drug nicknamed "liquid sunshine" - to meet him and his opponents, who denounce him as peddling a dangerous substance.

(Prozac Diary is tomorrow at 11.20pm on BBC2)