 But as I studied the evidence, I noticed something that I couldn't ignore. The forces that are making us depressed and severely anxious are, at the same time, making even more people unhappy. It turns out that there is a continuum between unhappiness and depression. They're still very different in the same way that losing a finger in a car accident is different from losing an arm and falling over the street is different from falling over the cliff. But they are connected. The book Lost Connections by Johan Hari.