Patients with depression are being advised to visit their GP for advice after British research suggested pills to treat the condition are largely ineffective.
And New Zealand's drug buying agency is warning people not to stop taking anti-depressants, despite clinical trials in Britain finding they work no better than a placebo.
NZ doctors say they are concerned some patients may stop taking their medication as a result of the study but they say the research is not new and may be misleading. She's concerned at research from the university of hull which found anti-depressants may not be effective.
The study examined 47 clinical trials of Eli Lilly and Co's Prozac, also known as fluoxetine, Wyeth's Effexor, also called venlafaxine; GlaxoSmithKline's Paxil, also called Seroxat or paroxetine; and Bristol-Myers Squibb Co's drug Serzone, also called Nefazodone. It found a placebo or sugar pill worked almost as well.
"The difference between the improvement on placebo and the improvement on the medication isn't all that great for most patient groups," says Professor Irving Kirsch.
But the drug companies are disputing the findings.
Richard Tiner from the British Pharmaceutical Industry says the regulatory authorities looking at all the evidence have determined they do work better than placebo.
And NZ experts say the research is not new. Judi Clements from the Mental Health Foundation says it is known that for mild to moderate depression anti-depressants are not necessarily the first port of call.
But the experts say pills are highly effective for people with severe depression and the treatment often takes months to work - not the six weeks the British researchers spent with some patients.
New Zealanders spent $30 million on anti-depressants last year - over one million prescriptions in all - and that is up 12% on the year before.
The Mental Health Foundation says that growth may be due to the fact that talking therapies such as psychotherapy, which work extremely well for some, are not publicly funded and at about $60 per session are expensive.
"Obviously for some paying those therapies is going to be a barrier, a total barrier," says Clements.
The commission wants the government to put more money in to break that barrier down.
Researchers at the University of Hull reviewed a series of studies, both published and unpublished, on four antidepressants, looking at whether a person's response to these drugs hinged on how depressed they were before getting treatment.
They found that compared with placebo, the new-generation antidepressant medications did not yield clinically significant improvements in depression in patients who initially had moderate or even very severe depression.
The study found that significant benefits occurred only in the most severely depressed patients.
Pharmac medical director Peter Moodie says people who take anti-depressants should talk to their doctor or health professional. He says they need to discuss whether the medication is working for them and should not just stop taking them.
Dr Moodie says Pharmac plans to carefully analyse the findings.
Prescriptions for antidepressants in New Zealand surpassed one million in 2006/2007 for the first time and in the last two years the number of anti-depressant prescriptions to middle aged Kiwis aged between 45 and 64 has risen by 69%, according to Ministry of Health figures.
United Future health spokesperson Judy Turner believes the figures are worrying.
"Coupled with new findings from a British university review casting doubt over the effectiveness of anti-depressant medication, the huge number of New Zealanders ingesting anti-depressants raises concerns about how we are treating depression in this country," says Turner.
But the Researched Medicines Industry Association says anti-depressants have saved lives and should not be dismissed.
Association chairwoman Dr Pippa MacKay says there are studies which show people who have had relapses of the illness need long term treatment.
