New research published in Biological Psychiatry shows that antidepressant drugs may help the immune system fight serious illness, including HIV and even cancer. The study suggests that antidepressants enhance the activity of our body white blood cells, which are key elements of the immune system.

White blood cells (WBC) is also considered as natural killer (NK) cells. WBC can attack infected or cancerous cells, releasing agents that induce apoptosis or "cell suicide." These natural killer cells are especially active against viruses.

The research emerged from findings that stress and depression impair functions of NK cells and can even accelerate the progress of HIV/ Aids. The study leader, Dr. Dwight Evans of University of Pennsylvania in Philadelphia said that NK cell function in HIV infection may be enhanced by selective serotonin re-uptake inhibition and substance P antagonism.