Depressed people often think intensely about their problems. These thoughts are called ruminations; they are persistent and depressed people have difficulty thinking about anything else. Numerous studies have also shown that this thinking style is often highly analytical. They dwell on a complex problem, breaking it down into smaller components, which are considered one at a time…
Many other symptoms of depression make sense in light of the idea that analysis must be uninterrupted. The desire for social isolation, for instance, helps the depressed person avoid situations that would require thinking about other things. Similarly, the inability to derive pleasure from sex or other activities prevents the depressed person from engaging in activities that could distract him or her from the problem. Even the loss of appetite often seen in depression could be viewed as promoting analysis because chewing and other oral activity interferes with the brain’s ability to process information.
But is there any evidence that depression is useful in analyzing complex problems? For one thing, if depressive rumination were harmful, as most clinicians and researchers assume, then bouts of depression should be slower to resolve when people are given interventions that encourage rumination, such as having them write about their strongest thoughts and feelings. However, the opposite appears to be true. Several studies have found that expressive writing promotes quicker resolution of depression, and they suggest that this is because depressed people gain insight into their problems.
[One of the big lessons I took from my own therapy, which lasted nearly ten years, is to listen to my body. Depression, like anxiety or impotence, often can be our body's way of telling us something (we don't want to hear). Feelings of emptiness aren't problems per se; they are indicators of problems in most cases. This is why any pharmaceutical approach to mental health is only half an approach. Without some form of talk therapy, without an attempt to understand ourselves more deeply, we risk fooling ourselves, and preserving our maddening behaviors. This is the thing about being human: we can handle a tremendous amount of stress, but there are things – ideas, even – that we just can't live with. Depression may be a good mindset for sussing out those ideas. Says Wittgenstein: "The way to solve the problem you see in life is to live in a way that makes the problem disappear." -Ed.]