A while ago a friend recommended Matthew Walker's book Why We Sleep: the new science of sleep and dreams. "It changed my life," she said. I can see why she said it. It's full of fascinating insights about what we do during those hours that constitute about a third of our life and why we need to pay more attention to the need for sleep. Walker offers some tips too. One question I often ask clients is how well they are sleeping. It's one of those telltale signs about mental hea