Causes of Depression
Martin Seligman, a noted secular researcher on depression, reflected on its causes:
I have spent the last twenty years trying to learn what causes depression. Here is what I think. Bipolar depression (manic-depression) is an illness of the body, biological in origin and containable by drugs. Some unipolar depressions, too, are partly biological, particularly the fiercest ones. Some unipolar depression is inherited. If one of two identical twins is depressed, the other is somewhat more likely to be depressed than if they’d been fraternal twins. This kind of unipolar depression can often be contained with drugs, although not nearly as successfully as bipolar depression can be, and its symptoms can often be relieved by electroconvulsive therapy.
But inherited unipolar depressions are in the minority. This raises the question of where the great number of depressions making up the epidemic in this country come from. I ask myself if human beings have undergone physical changes over the century that have made them more vulnerable to depression. Probably not. It is very doubtful that our brain chemistry or our genes have changed radically over the last two generations. So a tenfold increase in depression is not likely to be explained on biological grounds.
I suspect that the epidemic depression so familiar to all of us is best viewed as psychological. My guess is that most depression starts with problems in living and with specific ways of thinking about these problems.
I generally agree with Seligman, but I disagree that all severe unipolar and bipolar depression is only a physical illness of the body. It certainly can be the problem, and physical and chemical imbalances should definitely be considered in severe cases. But I have found that many severe depressions have a definitive spiritual component which is overlooked in the secular world and often in our churches.
For Spanish, see http://www.ficmm.org/blog