A new study suggests that antidepressant drugs can also battle cancers, including colorectal cancer.

HealthDay News reports the class of drugs are selective serotonin reuptake inhibitors (SSRIs), such as Prozac, Paxil and Zoloft

According to Georgetown University Medical Center and a Canadian research institute, drugs that treat depression by manipulating the neurotransmitter serotonin in the brain may also affect the patient's immune system in ways that are not yet understood.

Researchers discovered that serotonin is passed between key cells in the immune system, and that the chemical is specifically used to activate an immune response

A neuroscientist says Wednesday that regular users of the drug ecstasy can cause extensive damage to their immune systems, while those suffering depression induced by the drug may be more difficult to treat.

The methamphetamine has been linked to psychiatric illnesses, but Dr. Thomas Connor, of Trinity College Dublin, believes it may also place physical health at risk