Those who say that antidepressants are not good and that only rich housewives, who sit all day long and drink martinis, use them, are in for a surprise. It's likely that in the nearby future, these types of drugs will become, along with aspirin, omnipresent in the handbag or rucksack of us all.

Scientists from Georgetown University Medical Center and a Canadian research institute found that drugs that treat depression by manipulating the neurotransmitter serotonin in the brain may also affect the user's immune system.

Although these might help the organism to fight against various diseases, the team warns that drugs like Prozac, Zoloft and Paxil could also have a negative effect.

"The wider health implication is that commonly used SSRI antidepressants, which target the uptake of serotonin into neurons, may also impact the uptake in immune cells," said Gerard Ahern, Ph.D., assistant professor of Pharmacology at Georgetown and lead researcher on the study.

Ahern says that while it may be possible that SSRI drugs may restore a healthy immune function in people who are depressed and prone to infections, it is possible that they might also bolster immunity to the point that they trigger autoimmune disease

"At this point we just don't know how these drugs might affect immunity, so we really need to clarify the normal role of serotonin in immune cell functioning," Gerard Ahern also said.

"The novelty is that we reveal a potential communication, involving the transmitter serotonin, between immune cells that is normally only found between neurons."

In the brain, serotonin transmission between neurons is associated with feelings of pleasure, mood, and appetite, and the class of antidepressants known as SSRIs keeps serotonin active within the synaptic spaces between neurons, enhancing the chemical's positive effects.

Up until this discovery, it has been thought that only neurons reply on chemical communication, but researchers have shown that some immune cells also use serotonine to quickly excite a T-cell response.