A study has shown that anti-depressants may do more than improve the symptoms of depression. They also help to protect the brain in people having repeated bouts of depression.
Researchers have long known that the hippocampus (a part of the brain responsible for learning and memory) is usually smaller in people having a history of depression as compared to those having no depression. The exact reason for the shrinking of the hippocampus in prolonged depression is not known but the researchers feel that the release of stress hormone (such as cortisol) during depression may be responsible for damage to the brain cells.
Recently, the scientists conducted a study on 76 women, 50% of whom had a history of repeated bouts of depression while the rest had no depression. At the start of the study the hippocampus region of the brain was measured in all the participants using MRI (Magnetic Resonance Imaging). The MRI findings showed that not only was the size of hippocampus small in depressed women but also that its size was determined by the duration for which they continued the antidepressants i.e. those depressed women who took medications for less than the recommended time showed greater shrinkage of hippocampus.
Hence, the study shows that apart from preventing the relapse of depression in patients with repeated bouts of depression, the antidepressants also protect against brain volume loss associated with depression.
But how do antidepressants help to prevent the shrinkage of brain? According to researchers, the antidepressants can do this by controlling the release of stress hormones. In fact, some evidence shows that these medications can also increase cell proliferation in certain areas of the brain.
It has been observed that the hippocampus shrinkage is more in patients who stop taking antidepressants earlier than the recommended period. Usually doctors recommend 6-9 months of treatment for depression but some patients stop taking their medication as soon as they start feeling better (i.e. symptoms start improving). It is these untreated days, which cause the depression to relapse, and also affects the size of the hippocampus. Hence, simply by following the prescription till the recommended period, individuals having depression can prevent the shrinkage of the hippocampus.
Now that it is known that antidepressants can protect brain volume loss researchers are working towards finding out whether long-term treatment with antidepressants can also help in restoring the normal size of the hippocampus.