Depression, Damage, and Regeneration: The Effects of Hippocampal Atrophy

For years researchers have thought that brain damage, specifically shrinkage of the hippocampus, causes depression. However, a new comprehensive study published in Molecular Psychiatry proves that the relationship is reversed: recurrent depression causes brain damage.

The study compared the hippocampus size of 1,728 people who suffer from major depression and 7,199 healthy subjects using clinical histories and MRI scans to obtain images of the brain. The study included populations from the US, Europe, and Australia. The findings were consistent and conclusive; hippocampal atrophy, or shrinkage, occurred in those who experienced multiple depressive episodes, particularly those whose depression emerged prior to the age of 21. Hippocampal changes were not observed in healthy people or people who had only experienced a single episode of depression.

The Emotional Control Room

The hippocampus is one of the most vital and fascinating parts of the brain. Located under the cerebral cortex, it is a central component of the limbic system–the emotional center of the brain–and is responsible for forming, consolidating, and storing memories, emotional learning and regulation, decision-making, creativity, empathy, and spatial orientation. Hippocampus abnormalities are implicated in a range of cognitive and emotional disorders, including Alzheimer’s disease, schizophrenia, and transient global amnesia. Researchers have found that traumatic events and severe stress can cause shrinkage of this area of the brain, with significant changes observed in both men and women who suffer from Post-Traumatic Stress Disorder as the result of sexual assault or combat.

Hippocampus Shrinkage and Depression

In the case of depression, atrophy of the hippocampus impairs the ability to experience a healthy range of emotions and to regulate those emotions in a normal way. You may be less able to control your impulses and adapt to change while becoming predisposed to negative thought patterns that are difficult to break out of. You may be more likely to engage in self-destructive activity, including substance abuse. Hippocampal shrinkage also damages cognitive functions and interferes with the process of creating memories, which has a profound impact on both behavior and the ability to form a stable, realistic, and cohesive sense of self. Memory dysregulation can be a key factor in depressive experiences and closely inform both emotional states and your overall identity. Co-author of the study, Professor Ian Hickie from the Brain and Mind Institute, notes:

Your whole sense of self depends on continuously understanding who you are in the world – your state of memory is not about just knowing how to do Sudoku or remembering your password – it’s the whole concept we hold of ourselves.

Hippocampal changes also interfere with your ability to form and maintain healthy social relationships and make good social decisions. A 2014 study found that damage to the hippocampus can hinder flexible cognitive and social behavior by preventing you from accurately interpreting and responding to information. Social bonding is impaired, as is accurate judgment of character, and even your ability to use language effectively.

The Self-Healing Brain

Dr. Hickie’s study is a testament to the importance of early intervention in major depression; by seeking treatment during your first depressive episode, you can prevent damage to your brain. However, it is never too late to enter treatment. The brain is a remarkably adaptable and regenerative organ, and the hippocampus is a particularly resilient area. While depression can cause profound changes in the hippocampal structure, so can effective mental health treatment–in positive ways. The possibilities of neuroplasticity are only starting to be fully understood, but there is concrete evidence that medical intervention can engage the self-healing abilities of the brain and reverse shrinkage to restore the brain to a healthy state. Research indicates that people who have experienced hippocampal damage as the result of recurrent depression are best served using a combination of Cognitive Behavioral Therapy and antidepressant use. As such, it is crucial to connect with comprehensive treatment that integrates both psychotherapy and pharmacological approaches to optimize your ability to heal emotionally, cognitively, and physically, and restore balanced function.

Bridges to Recovery offers complete, holistic care that combines the most effective therapeutic modalities available to treat major depression. Our skilled clinicians use modern, evidence-based therapies to help you unlock your potential and create the life you want. Contact us for more information about how we can help you or your loved one suffering from depression or any other mental health disorder.