TO READ: Depression gene enlarges "negative" brain region
If you're clinically depressed, your brain's structure is probably different than that of your healthy friends. That's right -- while the use of biochemicals such as serotonin is undoubtedly different in depression, as we've heard for years, there are gross physical differences in the brain tissue as well. Several research studies have demonstrated that numerous regions of the brains of people with depression differ from that of non-depressed people -- usually certain areas are smaller in depressed people. Now, there's evidence that the "negative emotions" part of the brain is bigger in those with depression.

Last week in the journal Biological Psychiatry, scientists reported their studies of a particular gene, the serotonin transporter gene (SERT), which has two forms, known as short and long. If you have two short SERT genes (one from each parent), you're likely to have a bigger "pulvinar" in your brain. The pulvinar region handles negative emotions. People in the study who had depression had pulvinars 20% larger and with 20% more nerve cells than people with one or two long genes. Researchers believe about 17% of the population has two SERT genes.

The SERT gene also affects the nerve cells' use of the neurotransmitter serotonin. Prozac, Zoloft and several other antidepressants act by keeping serotonin more available for cells to communicate.

How does this new information help us? "The brain is wired differently in people who have depression, and probably from the point of view of treatment, we should try to identify these people as early as possible and intervene before the 'hard-wiring' gets altered," the lead researcher told Reuters.