By Adam Brimelow
BBC radio health correspondent
It is estimated that about one in four of us experience mental illness in our lifetimes.
'Talking therapies' can help people cope with depression
There is strong evidence that many patients could be helped by psychological therapy.
But the lack of specialists means many GPs feel they have no option but to prescribe antidepressants.
Now a senior government adviser has called for 10,000 more therapists to tackle what he calls one of the biggest causes of misery in our society.
Lord Layard, a Labour peer and director of the centre for economic performance at the London school of economics, says the therapists should be trained in cognitive behavioural therapy (CBT), and should work from a network of dedicated psychological centres across the country.
"The best way to organise this is on the treatment centre model, so that there's proper supervision, a proper centre where people can be trained, where their work can be monitored."
Lord Layard also wants to see waiting time targets for psychological treatment followed up by the health watchdog the Healthcare Commission within the next five years.
He says it's got to be the top priority for the NHS.
"Most of these conditions are ones which can respond to psychological therapy.
"So it would both improve peoples' lives enormously and also save the rest of us a lot of money if we tackle these problems. Just leaving people to fester in that situation is a disgrace."
CBT normally involves about 12 sessions over two or three months.
The aim is to tackle distress by helping patients to pinpoint - and then change - thoughts and actions that cause emotional problems.
A panic attack patient may be convinced he's dying if his heart starts racing.
That belief makes the reaction even worse - even if the medical evidence shows he's fine, so CBT will help the patient to get over that belief, therefore avoiding further panic attacks.
There's a lot of evidence that this approach works.
Professor David Clark is an expert on CBT based at the Maudsley hospital in London. He's exasperated that it's not more widely available.
"The tragedy is that these problems blight peoples lives.
"Relationships break up, people lose their jobs, people are unable to work although they've got great abilities, and many people become hopeless, and a number of people are driven to make suicide attempts because of that."
People with mental health problems have the lowest employment rates of any disabled group.
Independent think-tank The Sainsbury Centre says when the costs of lost work, care and other factors are added together, the overall economic burden of mental illness is more than £75 billion a year.
Labour promised to improve access to behavioural therapies in its election manifesto.
Health Secretary Patricia Hewitt has a keen personal interest in mental health, stemming largely from her experiences as a constituency MP.
Lord Layard is confident there will be what he calls a "major transformation" in this area - but he admits it will take substantial resources.
And as the NHS grapples with growing deficits, it could present a serious test of political commitment.
Dr Rebecca Rosen is a GP in Woolwich, east London - a deprived community with a lot of mental health problems.
She regularly sees patients who would benefit from psychological therapy. But there's a wait of around nine months for CBT which is supposed to be offered to patients with depression.
Dr Rosen says the delays are a huge frustration.
"Quite often people have been living with very difficult psychological symptoms for a long time before they even come here.
"And you can just see the look of disappointment on their faces when you tell them you believe they will benefit from CBT, but I warn them that there may be a nine month wait".
It's a common problem for GPs. Around 30% of their consultations relate to mental health problems.
This is one of the government's big clinical priorities and, while there have been improvements in some services, GPs often feel that for patients with problems like anxiety or depression they have little option but to prescribe antidepressants, usually a type of drugs called SSRI's.
In 2003 there were almost 20 million prescriptions for these, mainly for patients with mild depression.
Yet official guidance for doctors from the National Institute for health and Clinical Excellence says psychological treatment should be offered first.