Unhappiness itself is not the problem—it is an inherent and unavoidable part of being alive. Rather, it’s the harshly negative views of ourselves that can be switched on by unhappy moods that entangle us. It is these views that transform passing sadness into persistent unhappiness and depression. Once these harsh, negative views of ourselves are activated, not only do they affect our mind, they also have profound effects on our body—and then the body in turn has profound effects on the mind and emotions. Prof Mark Williams