300 actress Lena Headey was diagnosed with clinical depression as a teenager, and still suffers from the condition. Headey, whose school days were "really hard", blames her troubled childhood for triggering her continuing depression.

She says, "I was diagnosed when I was 15, and it comes and goes. I may suffer from it once or twice a year, but I now recognize it and deal with it. I don't use medication because I'm so worried about becoming dependent on it, but I can understand people who do, because you do go through the most horrendous feelings of isolation."

The 33-year-old star, who once ran away from home as a teen, occasionally has suicidal thoughts today. She says, "When the depression comes, it's very intense and you can't see beyond it."