Newborn mice given Prozac
grow up depressed
17:00 26 October 04
NewScientist.com news service
Mice treated with the antidepressant Prozac early in life grow into adults with emotional problems, a new report concludes.
Whether the drug has the same effect on people is unknown. But the result will add to the growing debate over what risks Prozac (fluoxetine) and similar SSRI drugs (selective serotonin reuptake inhibitors) pose for young children and unborn babies.
"If they really need these drugs, people should take them. They can be life savers," says Jay Gingrich, a psychiatrist at Columbia University in New York City, US, who led the research. "But it is a little bit alarming to find they might carry risks that aren't apparent until later in life."
Researchers began injecting mice with fluoxetine four days after birth until they were 21 days old. Nine weeks after their last injection, the adult animals were given a series of behavioural tests designed to assess their level of anxiety and depression.
The team found that rodents who received drug as newborns were more intimidated by new surroundings and moved more slowly to avoid painful shocks compared to controls. "They are more inhibited in novel situations," says Gingrich. "Extrapolating to people, we'd say the mice are showing symptoms of anxiety and depression or emotional problems."
Suicidal thoughts
"It's fascinating," says Tim Oberlander, a developmental paediatrician at the University of British Columbia in Vancouver, Canada. "It suggests these chemicals can cause crucial changes in the developing brain."
SSRIs work by increasing the level of the neurotransmitter serotonin in the brain and can be extremely effective in treating depression. They have been widely prescribed and make huge amounts of money for the drug companies that sell them.
But the drugs have become the focus of some controversy. Recently, for example, GlaxoSmithKline was accused of withholding data from clinical trials, the results of which suggested that depressed children taking their SSRI drug Paxil (paroxetine) had more suicidal thoughts than placebo controls.
