A stressful event increases the risk of developing depression later in life. Many people feel depressed and most times nothing is done to treat depression.
Studies have shown that major depression can cause brain damage. In fact, the studies state that they can change the shape of certain parts of the brain.1
Let’s briefly examine what depression is before we look into the effects depression has on our brain.
What Is Depression?
Depression is a common and a serious medical illness that negatively affects how you feel, think, and act. Depression can result in a person feeling sad. It also causes the person to lose interest in activities that were once enjoyed. Depression also changes how the person functions both at home and workplace.2
Can Depression Cause Brain Damage?
Many scientists and researchers believe that major depression or depression if not treated can cause brain damage.
It is popularly believed that the emotions dwell in the heart. However, Science has taken a different approach and has stated that the emotions are seated in the brain.
Depression primarily affects three parts of the human brain.3
[vs slide=”1″ slide_title=”Amygdala”]
Amygdala is the region of the brain associated with emotional processes. It is part of the limbic system – a set of brain structures located on both sides of the thalamus that supports a variety of functions including emotion, behavior, motivation, and long-term memory.
The amygdala is activated when a person recalls emotionally charged memories, such as a frightening situation. Activity in the amygdala is high when the person is sad or clinically depressed.4 This increased activity may continue even after the recovery from depression.
[vs slide=”2″ slide_title=”Thalamus”]
Thalamus is that part of the brain that is responsible for transmitting information from the sensory receptors to the areas of the brain where it can be processed.
It identifies sensory information transmitted to the brain including auditory (relating to hearing or sound), visual, tactile (relating to touch), and gustatory (relating to taste) signals.
Some research suggests that bipolar disorder may result from problems in the thalamus, which helps link sensory input to pleasant and unpleasant feelings.5
[vs slide=”3″ slide_title=”Hippocampus”]
The hippocampus is a small part of the brain but an important part of the limbic system. This part of the brain is mainly associated with memory – in particular, long-term memory – and emotional responses.
There are studies that show that the hippocampus in depressed individuals is much smaller than individuals who are not depressed.6
Hippocampal volumes of subjects with a history of major depressive episodes were compared to the volumes of normal subjects using volumetric magnetic resonance images. Subjects with a history of depression had significantly smaller left and right hippocampal volumes. The degree of reduction in the hippocampal volume was proportional to the total duration of major depression. These results suggest that depression is associated with hippocampal atrophy.7
Can The Brain Damage Be Reversed?
There is a study stating that the functions of the hippocampus can be improved with the right antidepressants with no structural changes of the hippocampus.8
The study involved 38 subjects with major depressive disorder and 33 healthy subjects. The 38 subjects with major depression were provided with antidepressants. The results show that the treatment with antidepressants did not change the hippocampal volume but there was a significant improvement in the memory function.
Although the study shows an improvement in hippocampal functions, more research is required in the area to make a concrete conclusion.
|↑1||Sapolsky, Robert M. “Depression, antidepressants, and the shrinking hippocampus.” Proceedings of the National Academy of Sciences 98, no. 22 (2001): 12320-12322.|
|↑2||What Is Depression?. American Psychiatric Association.|
|↑3||What causes depression?. Harvard Medical School.|
|↑4||Yang, Tony T., Alan N. Simmons, Scott C. Matthews, Susan F. Tapert, Guido K. Frank, Jeffrey E. Max, Amanda Bischoff-Grethe et al. “Adolescents with major depression demonstrate increased amygdala activation.” Journal of the American Academy of Child & Adolescent Psychiatry 49, no. 1 (2010): 42-51.|
|↑5||Frazier, Jean A., Sufen Chiu, Janis L. Breeze, Nikos Makris, Nicholas Lange, David N. Kennedy, Martha R. Herbert et al. “Structural brain magnetic resonance imaging of limbic and thalamic volumes in pediatric bipolar disorder.” American Journal of Psychiatry 162, no. 7 (2005): 1256-1265.|
|↑6||Frodl, Thomas, Eva M. Meisenzahl, Thomas Zetzsche, Christine Born, Constanze Groll, Markus Jäger, Gerda Leinsinger, Ronald Bottlender, Klaus Hahn, and Hans-Jürgen Möller. “Hippocampal changes in patients with a first episode of major depression.” American Journal of Psychiatry 159, no. 7 (2002): 1112-1118.|
|↑7||Sheline, Yvette I., Po W. Wang, Mokhtar H. Gado, John G. Csernansky, and Michael W. Vannier. “Hippocampal atrophy in recurrent major depression.” Proceedings of the National Academy of Sciences 93, no. 9 (1996): 3908-3913.|
|↑8||Vythilingam, Meena, Eric Vermetten, George M. Anderson, David Luckenbaugh, Eric R. Anderson, Joseph Snow, Lawrence H. Staib, Dennis S. Charney, and J. Douglas Bremner. “Hippocampal volume, memory, and cortisol status in major depressive disorder: effects of treatment.” Biological psychiatry 56, no. 2 (2004): 101-112.|