Childhood depression tends to be more common in inner cities, being most frequently related to serious social deprivation, bullying, domestic violence, wartime experience and famine. It is, for example, a serious problem among children who are traumatised refugees.

It's very clear from Biblical history and Jewish history that Jewish monotheism wasn't developed in an instant, that it became gradually the accepted norm. But undoubtedly, Jewish ancestors were polytheists.

Childhood is not dead. Children were worse off when we were hunter-gatherers; they were threatened in medieval times and exploited during the Industrial Revolution. Was it any better in the time of Charles Kingsley or Charles Dickens?

I was born with my moustache and, no, I've never been tempted to shave it off. I don't spend a lot of time worrying about my face and, like Gilbert and Sullivan's Katisha, my best feature is my left shoulder-blade.

People think I appear on television to promote my image. That's not fair. I hate filming. I turned down 'Strictly Come Dancing.' But television is a wonderful opportunity to promote scientific ideas. 'Super Doctors' is a very thoughtful piece.

I don't believe in regretting - one should try to move on. My mum was good at that. She was deeply in love with my father, and he died when I was nine. She remarried, and her second husband died, too. I saw the grieving process she went through. My mother had this way of moving on. It was a fine trait.

Women of child-bearing age steadily run out of eggs by the continuous process of cell death. While reading a copy of the Guardian carefully from cover to cover, a normal woman will have lost on average two eggs - while, typically, a normal man will have made 70,000 new sperm.