Neurotransmitters
Antidepressants are believed to work by helping the brain's neurotransmitters, which are needed for normal brain function and help control the mood and functions in thinking, sleeping, eating, response to pain and other actions. Because they have to work at various tasks within the body, antidepressant medication slows down their removal or helps to increase the levels of these neurotransmitters in the brain. This restores the brain's chemical balance to help relieve symptoms of depression. Chemicals in the brain can return normal function to people suffering from extreme sadness, hopelessness and lack of interest in life, ill effects experienced by people with depression. The work of antidepressants has also been successful in the treatment of people with eating disorders, chronic pain and other disorders that often carry depression with them. But scientists are continuing to study the actions of antidepressants.
New Cells
Researchers at Yale School of Medicine found that antidepressants increase the presence of a growth factor in the brain to cause the proliferation of new cells, it was reported at the Proceedings of the National Academy of Science in March 2007. A protein, called vascular endothelial growth factor (VEGF) was found to bring about the new cell growth. The researchers administered antidepressant medications to rodents, which increased the VEGF levels. Ronald Duman, senior author of the research, had earlier found that stress decreases VEGF in the hippocampus, the region of the brain involved in mood, emotion and short-term memory. This might cause the loss of brain cells when there is depression. Therefore, increasing those cells through antidepressants helps return the brain to normal functioning.
Growth Factors
Researchers at Emory University School of Medicine found that the widely used antidepressant and painkiller amitriptyline actually impersonates the brain's own growth factors, it was reported in the June 26, 2009 issue of Chemistry and Biology. Amitriptyline and similar antidepressants were thought to just increase the levels of certain messenger chemicals, serotonin and norepinephrine, which transmit messages from nerve cells to nerve cells. Scientists at Emory discovered the antidepressant directly stimulates molecules that help neurons grow and resist toxins. Researchers have also been using magnetic resonance imaging (MRI) to observe changes in the brain when people take antidepressants. A study reported in the January 2003 issue of American Journal of Psychiatry found that patients given antidepressant medication had more robust activity in areas of the brain that controls focused attention. Those areas had lower activity before the antidepressants were given.
