More than a quarter of people are affected by anxiety or depression each year. But are some people more at risk than others? By studying groups of rhesus monkeys, Dr Ned Kalin from the University of Wisconsin in Madison found that individuals displaying a trait known as "anxious temperament" may be up to 50% more likely to go on to develop anxiety disorders later in life, and the same seems to be true in humans... Like this podcast? Please help us by supporting the Naked Scientists