The advent of unprecedented technologies drastically altering the behavior of children and adolescents, compounded by prolonged isolation from a once-in-a-century pandemic, may have negatively impacted the normal connectivity of the human brain among youth, leading to the current alarming increase of depression, anxiety, and suicidality among this population.
The human brain is comprised of multiple large-scale networks that are functionally connected and control feelings, thoughts, and behaviors. As clinical neuroscientists, psychiatrists must consider the profound impact of a massive societal shift in human behavior on the functional connectivity of brain networks in health and disease. The advent of smartphones, social media, and video game addiction may have disrupted the developing brain networks in children and adolescents, leading to the current escalating epidemic of mental disorders in youth.
The major networks in the human brain include the default mode network DMN , the salience network, the limbic system, the dorsal attention network, the central executive network, and the visual system. Researchers can use functional MRI to detect the connectivity of those networks. When blood flow increases concurrently across 2 or 3 networks, this indicates those networks are functionally connected. Hans Berger, who developed the EEG in , noticed electrical activity at rest and proposed that the brain is constantly busy, but his neurology peers did not take him seriously.
In the s, David Ingvar discovered that the highest blood flow in the frontal lobe occurred when a person was at rest. He labeled this phenomenon the DMN, comprising the medial fronto-parietal cortex, the posterior cingulate gyrus, the precuneus, and the angular gyrus. Interestingly, the number of publications about the DMN has skyrocketed since Ongoing research has revealed that the DMN is most active at rest, and its anatomical hubs mediate several key functions 5 :.
When another brain network, the attention network which is also referred to as the task-positive network , is activated consciously and volitionally to perform a task that demands focus such as text messaging, playing video games, or continuously interacting with social media sites , DMN activity declines. The DMN does not exist in infants, but starts to develop in childhood. Those tasks, which require continuous attention, deactivate the DMN.
