Dr Tom Black defended a group of anti-depressants, called Selective Serotonin Reuptake Inhibitors (SSRIs), and said, in his experience, they are "wonderful drugs" which change people's lives for the better.

Dr Black, who is a GP in Londonderry, was reacting to new research which indicates that new-generation anti-depressants work no better than dummy pills.

It follows a review of clinical trials that found that such drugs had no more effect than a placebo for mildly depressed patients and for most people suffering severe depression.

A group of experts, led by Professor Irving Kirsch, from the Department of Psychology at the University of Hull, analysed 47 clinical trials.

The researchers looked at four commonly-used antidepressants and the clinical trials submitted to gain licensing approval.

They included antidepressants regularly prescribed in the UK, including fluoxetine (Prozac), venlafaxine (Efexor) and paroxetine (Seroxat).

Dr Black, who is deputy chair of the British Medical Association's Northern Ireland GPs Committee, urged anyone concerned about the research not to stop taking their tablets.

"In my personal experience, this group of anti-depressants are a very effective group of drugs. They also have very few side-effects, they aren't addictive and patients tolerate them well," he said.

"Those are all very important considerations when prescribing these anti-depressants over other groups, such as diazepam which is addictive.

"It's important to remember this is just one trial that is completely outweighed by evidence that shows how efficient these drugs are."

Dr Black said between 5% and 10% of Northern Ireland people suffer some form of depression.

"To replace these drugs with other 'talking therapies' such as counselling would require tens of thousands of extra counsellors and psychiatrists. It just wouldn't be a practical answer, particularly when many patients have busy lives and just don't have time to come for counselling."

He also doctor said he believed the drugs were "wonderful".

"We need to be careful not to scare people away from using these drugs. That would not be in the best interest of patients," he added.

"These drugs are wonderful. They get people back to their families, their work and normal life."

Figures from the charity Mind show that 31 million prescriptions were written for anti-depressants in the UK in 2006. Of these, 16.2 million were for SSRIs.

Alison Cobb, policy officer at Mind, said: "This research is a serious challenge to the predominance of drugs in treating depression.

" Anti-depressants do help many people, but by no means all, and some people experience severe side-effects with them.

"Nine out of 10 GPs say they've been forced to dish out drugs because they don't have proper access to 'talking treatments' such as cognitive behavioural therapy, which are recommended as the first-line treatment for mild to moderate depression by the Government treatment advice body, the National Institute for Health and Clinical Excellence (Nice).

"The Government is making very welcome investment in new talking therapies services, but they won't be online for some time yet.

"We're asking GPs to consider prescribing alternative therapies. Exercise, for example, particularly 'green exercise' outdoors rather than in the gym, has been shown to be very effective in combating depression. Diet can also be an important factor."

Other treatments for depression

• Exercise: Helps some people with depression. Douglas Adams, author of The Hitchhiker's Guide to the Galaxy, said running helped him cope with depression.
• Friends: Talking through your feelings can help in mild depression with a friend or relative or in a self-help group.
• Cognitive behavioural therapy: Teaches you to challenge negative thoughts and feelings of hopelessness.
• Interpersonal therapy: Focuses on relationships and problems such as difficulties with communication.
• Counselling: Helps you think about the problems in your life and find new ways of dealing with them.
• Antidepressants: Increasingly seen as a second-line treatment, if exercise or talking treatments do not work.