The Saturday essay: The darkness that has brought humanity light

EVERY HUMAN being is liable to depression following bereavement, disappointment or failure. Depression is a normal psycho-biological response to loss which we share with other species, and which in origin is adaptive.

As Konrad Lorenz demonstrated, a greylag goose which has lost its mate droops, looks bedraggled, and loses its place in the dominance hierarchy. This adoption of a defeated stance protects the animal from attack at a time when it is vulnerable. Recovery is signalled by more aggressive behaviour which may result in the animal regaining its former status.

Something very similar occurs during human mourning. A period of depression following the loss of a loved partner is inescapable. It is a necessary precursor to adopting a new, more positive attitude to life either in solitude or with a new partner. Although depression in human beings is usually related to some kind of loss, it is not generally so simply explained.

Depression is probably the commonest symptom for which people seek help from a psychiatrist. It is an age-old affliction which was recognised by Hippocrates in the fifth century BC. It varies in severity from the transient diminution in vitality which follows temporary disappointment to the total despair of psychotic melancholia, in which the sufferer is deluded, inaccessible and suicidal.

To use the same word to describe such extremes seems inappropriate; but it does underline the fact that there is a continuum between mild and severe depression. We rightly regard severe depression as a pathological condition in urgent need of treatment. Because it often seems to afflict people for no obvious reason, we are apt to forget that it can be artificially induced in anyone, as the police in Communist countries discovered.

If a man is arrested in the middle of the night, given no information about his supposed crimes or about what is likely to happen to him, kept incommunicado in solitary confinement, separated from those he loves, and rendered ineffective by being given no occupation, he will usually present a picture of psychotic depression within four to six weeks.

It is not surprising that a person who has been deprived of everything that sustains self-esteem and makes life worthwhile becomes appallingly depressed. What is more difficult to understand is that the same emotions can be felt by someone who has a spouse, a job, and all the other accompaniments of fulfilment and happiness. Severely depressed patients, whatever their circumstances, resemble Communist prisoners in feeling guilty of crimes that they may not have committed; in feeling useless and helpless; in being convinced that they are unloved, unlovable and unloving; and in finding that life is no longer worth living.

Those who are prone to severe depression may be precipitated into this abyss by comparatively trivial adverse events. Such people behave as if they had no inner resources, nothing to bolster their self-esteem when things go wrong.

Something like one in 10 of the population of Western countries experiences a major period of depression during his or her lifetime; and women are twice as likely as men to suffer in this way. There is some evidence suggesting that episodes of depression are becoming more common. Perhaps this is because the condition is more readily recognised by doctors; but the increased frequency of divorce and the consequent break-up of family life may also contribute.

Severance of emotional ties is a frequent precipitant of depression at all ages; and research has shown that those who are fortunate enough to have a partner or relative in whom they can confide intimately are less prone to depression when things go wrong. But is clear that some people are much more prone to depression than others. Why is this?

Since the discovery of anti-depressant drugs, a huge amount of research has been aimed at elucidating the relation between depression and brain chemistry. Some modern antidepressants work by prolonging the time during which the neurotransmitter seratonin acts between nerve cells before it is removed or destroyed.

But it would be erroneous to conclude that depression was simply due to too little seratonin. Lithium is highly effective in the treatment of manic-depression; but lithium deficiency is not a medical condition. It is not always clear whether changes in brain chemistry provoke depression or whether depression causes changes in brain chemistry.

Many depressed patients have raised levels of the steroid hormones which are secreted by the adrenal glands in response to stress. Puerperal depression, which affects some women after childbirth, is almost certainly related to the sudden changes in levels of hormones which occur at this time.

The discovery of effective antidepressant drugs has been of great benefit to depressed patients, but has brought with it the risk that doctors in a hurry simply write out a prescription without bothering to investigate the precipitating causes of the depression.Depression is usually recurrent; every depressed patient needs to understand what factors may precipitate a further attack, and what measures can be taken to prevent one.

There is no doubt that genetics play an important part. Both manic depression and recurrent depression without any manic component runs in families. For example, the poet Tennyson, who was himself liable to depression, was the fourth child of 12. His father was a severely disturbed clergyman who suffered from recurrent depression, epilepsy, and from addiction to alcohol and laudanum. Of his 10 surviving brothers and sisters, one was an opium addict, one an alcoholic. One brother spent nearly all his life in an asylum, and another was almost as disabled by mental illness. All the remaining siblings had some form of mental breakdown.

But there is no single gene responsible for recurrent depression. The condition is determined by the complex interaction of a variety of genes, and is also influenced by environmental factors. Even if one of a pair of identical twins suffers from manic depression, the other twin does not necessarily develop the disorder. While it is true that the risk of developing manic-depression is increased if a parent or sibling has suffered in this way, it is not so much increased that the abortion of foetuses which might be at risk is justifiable.

We must remember that, although severe depression is a terrible affliction, it is derived from, and connected with, a response to loss which is originally adaptive. We therefore meddle with its origins at our peril. Also, we owe an immense debt to the many men and women of genius who have suffered from manic-depressive illness or recurrent attacks of severe depression.

As one German psychiatrist wrote: "If we could extinguish the sufferers from manic-depressive psychosis from the world, we would at the same time deprive ourselves of an immeasurable amount of the accomplished and good, of colour and warmth, of spirit and freshness. Finally only dried up bureaucrats and schizophrenics would be left. Here I must say that I would rather accept into the bargain the diseased manic-depressives than to give up the healthy individuals of the same hereditary cycle."

Anyone who doubts the connection between creativity and manic-depression should read Touched With Fire (The Free Press, 1993) by Kay Redfield Jamison. As Dr. Jamison's own research has shown, poets are particularly likely to suffer from manic-depressive illness. In an appendix to the text she lists a huge number of writers, composers, and painters who have been afflicted with one or other form of the disorder.

Severe depression renders those who suffer from it incapable of productive work, and inaccessible to psychotherapy. But the liability to depression may actually be a powerful spur to creative production in those who are gifted enough to make use of this way of coping with their vulnerability. For example, writing can be valuable both as a defence against depression and also as a way of overcoming it. It can help the writer to come to terms with loss, and restore a sense of being able to cope. It can bring a new sense of meaning to a life which has lost significance.

Writing can be a means of self-affirmation and self-expression for those who find these difficult to achieve in the give and take of ordinary social life. It can also be a means of self-exploration. Those who are prone to depression have little or no built-in self-esteem. They are unusually dependent upon external sources to boost or preserve any sense of their own value. Success and public recognition may temporarily serve as sources of self-esteem and may therefore compensate for the sense of inner emptiness which is so characteristic of depressives.

Graham Greene, whose recurrent depressions were so severe that his friends assumed that he was bound to commit suicide, wrote in his autobiography Ways of Escape: "Writing is a form of therapy; sometimes I wonder how all those who do not write, compose or paint can manage to escape the madness, the melancholia, the panic fear which is inherent in the human situation."

Balzac is one example of a writer who was, throughout his life, insatiable. He was hungry for love and hungry for fame. His mood swings were extreme, ranging from prodigious, manic overspending to suicidal depression. His fantasies were grandiose. He seems to have used his enormous debts as a spur to production. When writing, he dined at 6pm then slept till 1am. From 1 to 8am he worked. He then rested till 9.30, only to work again till 4pm. From 4pm to 6pm he might receive visitors. Then the cycle was repeated. He could keep this up for weeks.

This is an extreme example of using work as a defence against depression. Dickens is another example of a writer who used both his writing and other activities to stave off depression. In early life, he suffered intensely from his father's imprisonment for debt, and from the humiliation of his own consequent employment in a blacking factory when he was 12 years old. Nor did he really recover from his rejection by his first love, Maria Beadnell. A period of depression occurring in 1848 was reinforced by the death of his sister Fanny from tuberculosis. In August 1849, he described himself as suffering from "Extreme depression of mind, and a disposition to shed tears from morning to night."

Ceaselessly busy. Dickens often worked on several projects simultaneously. He was not only a productive novelist, but also a journalist and editor, an actor and producer, a social reformer, and a tireless walker who thought nothing of striding 15 miles or so through the countryside. But "the euphoria of effort was always followed by the reaction of despair". John Forster, Dickens's closest friend, wrote that Dickens "had not in himself the resources that such a man, judging from the surface, might be expected to have had... There was for him `no city of the mind' against outward ill, for inner consolation and shelter."

I referred earlier to the absence of inner resources which characterises those who are prone to depression. Dickens was so dependent on the plaudits of an audience that he hastened his own death by continuing to give dramatic readings from his books after medical advice had discouraged him from doing so. We sympathise with his suffering, but he would not have achieved what he did without it.

Many of the most valuable human beings who have ever lived have shown clear evidence of recurrent depression. What matters is that those who exhibit this liability should be able to use it productively. Like Tennyson's Ulysses, they "cannot rest from travel". Their aim should be the same as his: "To strive, to seek, to find, and not to yield."

The author's book `Churchill's Black Dog and Other Phenomena of the Human Mind' is published in paperback by Fontana