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.”