Millions of patients 'should not be prescribed antidepressants'
Millions of people should not be prescribed antidepressants because their brains resist the drugs, a study has indicated.
By Kate Devlin, Medical Correspondent
Published: 7:30AM GMT 14 Jan 2010
Half of patients do not respond when they are given the medications, which can be powerful tool in helping the depressed to feel better. Instead of raising levels of a "happiness chemical", called serotonin, in their brain, they lower them.
The researchers found with some brain cells "the more antidepressants try to increase serotonin production, the less serotonin (they) actually produce,” said Dr Rene Hen, from Columbia University in New York and a researcher at the New York State Psychiatric Institute, who led the study.
He and his team believe that the findings could lead to ways to identify patients for whom the drugs will not work, before they are prescribed expensive and ultimately pointless treatments.
But they also hope that their research could someday lead to ways to overcome the problem, so that the drugs can be used to help more people.
Their study, published in the journal Neuron, found that some brain cells reacted negatively to antidepressant medication.
Tests on mice show that the drugs had no such effect on the animals when they were genetically engineered to have more of these cells.
The team behind the study now plan to test their findings on a group of human patients.
They hope that drugs could be developed to prevent the actions of these cells and allow the medication to work as intended and increase serotonin production.
Most antidepressants, including selective serotonin reuptake inhibitors (SSRI's), such as prozac, work by increasing serotonin levels.
An estimated one in seven people will develop depression serious enough to need treatment at some point in their life.
Across England around 31 million prescriptions are written for antidepressants every year.
The Mental Health Foundation estimates that use of the drugs has doubled over the last 10 years.