Recent research regarding memory, anxiety, and depression expounds new parameters for their effects on everyday life.
Anxiety and depression affect up to 40 million adults in the U.S (or 18.1% of the population) each year. The Anxiety and Depression Association of America (ADAA) also reports that only 36.9% of those affected receive treatment for their mental illnesses.
A new study suggests a biological explanation for these prolific ailments.
Researchers at the University of Toronto Scarborough Campus (UTSC) found that the hippocampus may reveal clues about these illnesses.
What did the study conclude about how memory relates to anxiety and depression?
Understanding How The Hippocampus Affects Memory
The hippocampus, long associated with memory, also relates to the brain disease dementia. As some may know, dementia affects the brain’s ability to maintain memories. The hippocampus helps us to make new memories, which is why Alzheimer’s disease starts with memory issues.
However, the hippocampus also relates to learning and emotion along with memory. It has also been linked to schizophrenia.
The seahorse-shaped formation lies in the limbic system of the brain. It helps with spatial cognition, memory processing, and environment navigation. But two subareas in the ventral hippocampus gave researchers pause in this new study.
UTSC delved into the hippocampus’ relationship with memory, as well as emotion. They found that certain parts of the hippocampus might affect emotional regulation.
Specifically, they focused on the CA1 and CA3 subareas and their relationship with approach-avoidance conflict processing.
A Targeted Scope for More Insight
You can see in the image above that the hippocampus sits very close to the amygdala. That part of the brain also works as part of the limbic system in the brain. But the amygdala revolves mainly around fear, emotion memory, and other “flight” triggers.
Overall, the limbic system deals with memory and emotions, just like the hippocampus. That’s why the UTSC research team targeted approach-avoidance conflict processing.
Before the findings of this study, researchers thought the CA1 and CA3 parts of the hippocampus operated in a one-directional information flow. In theory, CA1 and CA3 should perform the same functions since they are both in the same “processing” circuit.
However, what the UTSC researchers found totally contradicted this fact. As Medicalxpress reported:
“…the CA1 and CA3 in the ventral hippocampus seem to do very opposite things in relation to conflict processing…It’s this strange bi-directional or oppositional effect, and that goes against traditional thinking of how information processing takes place in this part of the brain.” Rutsuko Ito of UTSC
The study suggests that the “approach” and the “avoidance” travel the information processing circuit differently. This may explain why anxiety and depression favor “avoidance” behaviors over “approach” behaviors.
The current findings show that approach-avoidance conflict processing may affect anxiety and depression. Moreover, it could even be involved in addiction and other aspects of motivational behavior.
Ito and the rest of team want to explore what other connections CA3 and CA1 have in the brain. These connections may reveal more information about memory’s relationship to anxiety and depression.
A Biological Explanation for Anxiety and Depression
So far, the UTSC researchers are only beginning to understand this new relationship.
Anxiety often involves obsessive combing through memories. Depression can manifest as intrusive thoughts based on biased retellings of your memories. We know that these illnesses are interlinked and maybe this study shows us that memory is the link.
Learning more about how the hippocampus processes information could lead to more than just understanding the relationship amongst anxiety, depression, and memory.
It could even lead to a way to reverse these illnesses or ways to prevent them — especially if the cause is biological.
Another UTSC researcher, Andy Lee, has a study of his own focused on patients with brain lesions. He and his team will study conflict processing and other aspects of approach-avoidance behaviors.