Brain hyperactivity. Maps showing the difference in the strength of brain connections between depressed subjects (left) and controls (right). Depressed subjects show much stronger connections, as evidenced by red colors in their maps. (Credit: Image courtesy of University of California - Los Angeles)

By Mariel Emrich, Columbia Grammar and Preparatory School

Clinical depression comes along with many other symptoms including anxiety, poor attention, memory issues, and sleep disturbances. Researchers at UCLA, including Andrew Leuchter, a professor of psychiatry at the Semel Institute for Neuroscience and Human Behavior at UCLA, believe that these multiple symptoms of depression may be linked to a malfunction involving brain networks. Therefore, they believe that depression is not directly linked to one part of the brain, rather it is due to the imbalance of chemicals in the brain connections. The researchers demonstrated that depressed people have increased connections among most brain areas. These patients have brains that are hyperconnected. This report, which was published in the online journal, PLoS One, allows scientists and researchers to view the brain differently and understand depression better.

The brain must be able to regulate its connections to function properly. The brain must learn how to synchronize and desynchronize itself in order to regulate mood, learn and solve problems. A depressed brain is able to function properly, but is unable to desynchronize and thus is not able to shut off the connections in the brain. The inability of scientists to control how different brain areas function together may explain why depression is not completely curable.

In the study, the researchers looked at the functional connections of the brain in 121 adults who were diagnosed with major depressive disorder. They measured the synchronization of brain waves to study networks among the different brain regions. The UCLA researchers used a new method called “weighted network analysis” to examine overall brain connections. The depressed patients showed increased synchronization across all frequencies of electrical activity, indicating dysfunction in many different brain networks. The area of brain that showed the most abnormal connections was the prefrontal cortex, which is involved in regulating mood and solving problems. When brain systems lose their flexibility in controlling connections, they might not be able to adapt to change. Therefore, when a depressed patient loses a relative due to a sudden death, this may trigger more symptoms.

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Mariel is currently a sophomore at Columbia Grammar and Preparatory School in New York City. She loves learning about science and particularly enjoys genetics, cancer research, radiology, and forensics.