Researchers used brain imaging to identify how patterns of brain connectivity the ability of different brain regions to talk to each other can affect a person's likelihood of developing common forms of mental illness. Individual regions of the brain have to team up to get things done. And like in any team, the key to working together is communication. The study was published in Biological Psychiatry.
Surprisingly, they found that brain regions that help process what we see may play a key role in mental health. The results show that a person's risk of mental illness broadly increases when the visual cortex has trouble communicating with brain networks responsible for focus and introspection. They found evidence that visual areas may be related to mental illness by their ability to communicate information between two higher-order cognitive networks.
Teasing out how risk for mental illness manifests in the brain could help researchers target interventions and therapies to where they matter most, the researchers say. In their analysis, the team drew upon data from 605 university students who participated in the Duke Neurogenetics Study. Each participant was asked to spend about 10 minutes relaxing in a Magnetic Resonance Imaging (MRI) scanner while the instrument recorded blood flow to different regions of the brain.
Participants also completed a comprehensive mental health assessment, and the researchers used these assessments to estimate each's "p-factor" score. The p-factor reflects recent observations that people with symptoms of one psychiatric disorder, such as anxiety, are also more likely to report symptoms of one or more additional psychiatric disorders, such as depression or bipolar disorder.
People who reported a greater number of or more intense psychiatric symptoms were assigned a higher p-factor score. All participants who were diagnosed with mental disorders were referred for treatment. They examined how the structure of the brain, such as the density of white or grey matter, maps onto the p-factor. They found that higher p-factor scores correlate with lower volume and less integrity of white and grey matter in regions of the brain that help complex coordinate movements with external stimuli, including visual input.
In the new study, they wanted to extend this analysis also to include the brain's functional circuitry. They consistently found that people with higher p-factor scores also had certain brain regions that didn't work together as well specifically four regions of the visual cortex that help us understand and recognize.
When they looked deeper into the data, they found that these visual networks specifically had trouble tapping into more complex networks responsible for focus, planning, and introspection. Difficulty focusing and planning has been linked to severe forms of mental illness, such as schizophrenia and severe depression. They will never make progress in the field of psychiatry until we can understand the biological origins of these diseases in people, said Theodore Satterthwaite, an assistant professor of psychiatry.
The more they can map the p-factor onto the brain and understand how it influences mental illness, the more we can come up with novel ways of intervening.