New Haven, Conn. Continued use of anti-depressants leads to new cell growth in an area of the brain known to suffer cell death and atrophy as a result of depression and stress, a study by Yale researchers shows.
Depression affects an estimated 12 percent to 17 percent of the population at some point during their lifetime. Anti-depressants are commonly prescribed for depression and other affective disorders, but the drugs therapeutic effects on the molecular and cellular level are not clearly understood.
"The findings of our study are that chronic administration of anti-depressants increases the number of neurons in the adult hippocampal ," said Ronald Duman, M.D.., professor of psychiatry and pharmacology. "This could explain in part how anti-depressants produce their therapeutic response." Duman was senior author of the study published Dec. 15 in The Journal of Neuroscience.
The hippocampus is part of the limbic brain that is involved in learning, memory, mood and emotion. It is one of only a few regions of the brain where production of neurons occurs in the adult brain of animals, including humans. Several studies have demonstrated that stressful experiences, both physical and psychological, lead to neuronal loss or atrophy in the hippocampus. Other studies show that anti-depressants can block this cell loss.
"In humans, brain imaging studies demonstrate that in patients with depression or post traumatic stress syndrome there is a decrease in volume of the hippocampus that is thought to be related to the neuronal atrophy and loss," Duman said. "The results of our study demonstrate that anti-depressants can reverse or block further loss of neurons in the hippocampus by increasing neurogenesis (new cell growth)."
Dumans laboratory has been studying the mechanism of action of anti-depressants in rodents for over 15 years. The researchers have focused on cellular actions of anti-depressants, looking at the role of the intracellular signal tra
Contact: Jacqueline Weaver