"Mental illness is Britain's great social inequality and the cost to society of not treating it is enormous. The past 30 years have produced a revolution in remedies for common mental illness, which is highly treatable, but very little of NHS resources are directed to delivering them.
"Anti-depressants are not so effective with normal depression [compared with more severe disorders] and they are being over-prescribed. In a proper health service, patients should have a range of treatments available.
"Cognitive behaviour therapy is at least as effective in the short term and more effective in the long term [as drugs] ... Offering psychological treatment is cost effective.
"If you take common depression, 85 per cent of people will have another episode in their lives. CBT substantially reduces the recurrence rate. You are removing the problem permanently - that is not true with medication.
"CBT would save the nation a lot of money because anxiety and depression make it difficult for people to work, and people with anxiety seek an awful lot of physical interventions.
"One of the reasons why there has not been more progress on this therapy in the past is that when you look at the costs and the benefits they do not occur across all government departments and agencies.
"It's fair to say that we are a bit therapy averse in this country. CBT is highly structured. People think it's just another talking therapy and that anyone is qualified to practise it, but in reality it's like the difference between normal surgery and keyhole surgery.
"Take panic disorder, where people experience repeated panic attacks which happen quite quickly, like palpitations. Normally people go along to their GPs and they will give them cardiac tests which will prove negative. They will be told there is nothing wrong, then get counselling, then be sent for CBT. What CBT does is takes their thoughts and tries to show people what is correct and what is a false belief.
"We've been doing work at the Maudsley where we condense the therapy into a week. Fast-tracking in a concentrated time has been very successful."
Professor David Clark is director of the Centre for Anxiety Disorders and Trauma at the Maudsley Hospital and head of the psychology department at the Institute of Psychiatry, Kings College, London. He was talking to Sophie Goodchild