A recent research review, published in Nature Neuroscience, suggests that social disconnection may be processed in the brain in the same way as the threat of physical harm. That is, when a person perceives that their relationship with another person is under threat, the brain responds by activating a basic ‘alarm system’. This alarm system sets in motion a range of neurophysiological processes that are the same, whether the threat is physical and in the environment, or perceived and based on individual judgment of a threat to social connectedness. This alarm system includes the amygdala, the anterior cingulate cortex and the insula, all of which are known for their roles in both threat- and pain-related processing.
What happens when this alarm system is activated? The sympathetic nervous system and hypothalamic-pituitary-adrenal axis go into overdrive, increasing inflammation and a compromising the immune system. These processes contribute to many diseases such as diabetes, those of aging, and cancer. New evidence suggests that these responses occur in response to perceived social isolation as well to a physical threat of harm.
On the other hand, how does social connectedness improve health? Research shows that being reminded of your social connections activates basic reward-related circuits that are also activated when learning to respond to beneficial environmental cues.