Health reporter, BBC News
Some people may prefer to see a therapist in person
The NHS should offer online psychological counselling for people with depression, a leading mental health expert says.
A Lancet study of online cognitive behaviour therapy (CBT) showed it more than doubled the chances of recovery.
Dr Tim Kendall, who led the drawing up of national guidelines on depression, called for online access to become part of the drive to widen access to CBT.
One in six people experience depression at some point in their lives.
Much has been said in recent years about a reliance on antidepressants, with prescriptions for the drugs increasing almost two-fold in a decade, from 18,424,473 in 1998 to 35,960,500 last year.
The National Institute of Health and Clinical Excellence (NICE) advises that psychological therapies should be used over antidepressants in mild to moderate cases.
And even in people with severe depression, therapy such as CBT, which focuses on helping people to solve problems and overcome negative, unhelpful or false thought patterns, can help when combined with medication, it says.
In the latest study, comparing real-time online therapy sessions with normal GP care, those receiving online treatment were 2.4 times more likely to have recovered eight months later.
The results of the trial of 200 patients in Bristol, London and Warwickshire are comparable to the results seen with face-to-face therapy, said study leader Dr David Kessler.
During the online sessions, in which a time slot is pre-arranged, a therapist and the patient communicate by a form of 'instant messaging'.
It is thought some people benefit from writing down their thoughts rather than talking about them.
Dr Kessler believes the technique's use within the NHS could widen access to CBT.
The government announced a £170m investment in "talking therapies" back in 2007, after it was estimated that the NHS in England needed 10,000 extra therapists.
Dr Kendall, chair of the NICE guidelines on depression and anxiety and a psychiatrist in Sheffield, said NHS capacity for psychological therapy was improving fast but care was still patchy.
"What's really good about this study is it's finding different ways of doing therapies which might suit some people better - some people will find it a big relief not to have to face a therapist.
"One of the other big pluses is it could cater for people with different languages.
"We should be thinking about this as an alternative under the Improving Access to Psychological Therapies programme."
Dr Kessler, who is a researcher at Bristol University and a practising GP, agrees that online therapy should be available on the NHS.
"It's very effective and it has the potential to widen access.
"It's more convenient for some people and it's good for hard-to-reach people - whether because of geography or disability - and you could offer online CBT in other languages."
He added that online therapy would not be suitable for everyone and the NHS needed to offer a choice.
A spokeswoman for the Department of Health said trusts should provide funding for CBT services according to local need.
She said the psychological therapies programme had now rolled out to 35 primary care trusts and more than 800 CBT therapists are now in training.
"By 2011, a total of 3,600 such therapists will have been trained and people will find it much easier to get this kind of therapy than they do now."