Is depression good for you?
Pills aren't the answer to helping many people recover from depression, says a report out this week. But there's growing evidence that gloominess could be a positive experience.
What depressed the cavemen? It may strike us as a particularly modern malaise for a time-poor, fast-paced society but a new reappraisal of depression suggests it has always been around.
A leading psychiatrist says that depression is not a human defect at all, but a defence mechanism that in its mild and moderate forms can force a healthy reassessment of personal circumstances.
Dr Paul Keedwell, an expert on mood disorders at the Institute of Psychiatry, King's College London, argues all people are vulnerable to depression in the face of stress to varying degrees, and always have been.
The fact it has survived so long - and not been eradicated by evolution - indicates it has helped the human race become stronger.
"There are benefits and that's why it has persisted. It's a tough message to hear while you are in depression but I think that there's a life afterwards," he says.
"I have received e-mails from ex-sufferers saying in retrospect it probably did help them because they changed direction, a new career for example, and as a result they're more content day-to-day than before the depression."
One woman left an abusive relationship and moved on, he says, and might not have done if depression had not provided the necessary introspection.
Similarly, unrealistic expectations are revised when depression sparks a more humble reassessment of strengths and weaknesses.
In Britain one in four men and one in five women are estimated to suffer depression during their lifetime, and one in 20 suffers it at any one time.
Dame Kelly Holmes has spoken in the past about how the depression she suffered in 2003 made her a stronger person, a year before her double-gold performance at the Olympics. Alastair Campbell has said it was the making of him.
But there are other qualities depression generates, not just resilience, says Dr Keedwell, author of How Sadness Survived.
"Psychological unease can generate creative work and the rebirth after depression brings a new love affair with life."
Aristotle believed depression to be of great value because of the insights it could bring. There is also an increased empathy in people who have or have had depression, he says, because they become more attuned to other people's suffering.
What is depression?
Depression can be traced all the way back to the Stone Age, say Dr Keedwell, when close-knit communities of about 50 people would have identified it quickly. The rest of the group would have rallied round and changes followed, such as a new role for the individual.
Some remote communities are more aware of it. The Banda tribe in Uganda calls it "illness of thought" and those affected are allowed time out from the group, a concession not extended to many with the condition in the UK.
The high and rising incidence in the UK and US - compared to countries like Brazil and Mexico - could be due to the breakdown of family bonds and the fragmentation of society. And compared to past decades, there are increased expectations of success.
Dr Keedwell says his theory does not cover severe depression, which is an illness accompanied by a catatonic lack of energy, cannot be worked through and requires the intervention of a GP
Anti-depressants, which were reported this week to have little clinical benefit for many patients, have a part to play, says Dr Keedwell, especially in severe depression. But an individual must address the social or emotional cause either on his own, with a loved one or with a professional.
"Don't beat yourself up about being depressed, in most cases it will run its course provided you take yourself out of the situation that caused it.
"I know that's an easy and glib thing to say, because I'm not a single mum living 12 floors up in a high-rise block. Sometimes it's not easy to escape but that's the fault of society, not the fault of depression."
GWB, not GDP
Politicians have recognised this and happiness is a word that has recently entered the political debate on both sides, with David Cameron saying that improving society's sense of well-being is one of the central political challenges of the times - GWB (general well-being) and not GDP (gross domestic product).
A happiness agenda is a laudable aim but one that is meaningless, says Phillip Hodson, a fellow of the British Association for Counselling and Psychotherapy, because happiness is not something you can buy in Tesco.
"Everybody's life is full of occasional misery and we are going to suffer. All life ends in grief, unless you are lucky and you and your loved ones all die simultaneously in some plane crash.
"So I applaud the government for trying but I think the happiness agenda can be simplistic. You can't legislate for happiness."
He agrees with Dr Keedwell that depression, however horrible, does imbue people with a useful resource.
"You would never ask for it or want it this way. But people who work through it, with a professional or with friends and family, for those people who have an awful journey, they are better travellers."
But identifying the cause and addressing it is easier said than done, says Stuart Summerfield, 68, from Chesterfield, who has suffered from depression throughout his adult life. Although he believes he has a genetic predisposition to it, he blames its severity on his possessive mother.
She never acknowledged his illness and made it difficult for him to seek help, but her death in 1999 relieved him of caring duties and sparked a recovery. He is now involved in running a self-help group.
"I don't think that knowing the cause is always the route out. Changing circumstances is a major part of it but it's not always something you can change. Sometimes the big problem is admitting what the situation is."
He concedes it has helped him in some ways because he has a new appreciation of life.
"They say adversity makes you stronger, so I should be Superman by now."
But it is an "awful journey" and not a price worth paying for longer-term gain.