"Friends" actor David Schwimmer believes he'll find true happiness only when he becomes a father, insisting the fulfilment of his other ambitions have failed to lift his bleak outlook on life.

"Basically, I don't think I'll truly be happy until I'm a father and a husband. There's a part of me that thinks, did the celebrity thing, did the entertainment thing, done plays, done TV, done film - done it," the actor was quoted by the Internet Media Database.

The star ensures he always has a full calendar of work lined up because he says he spirals into depression when he's relaxing at home. "So when you get to that philosophical 'What's life really about'. If you're a man, it comes down to being a father.

"It's a question that I ask myself a lot. I think I have moments of happiness, but I'm not generally happy."