Social isolation, cognitive decline, and cardiovascular disease risk

• Social inclusion is a fundamental need for humans.
• Social isolation is robustly associated with cognitive decline.
• Social isolation is robustly associated with cardiovascular disease risk.
• Future work can assess mediating role of cardiovascular decline.

Some of the first observations in early psychology regarding human nature involved the importance of social connections to mental health. Humans are hypothesized to have a fundamental need to belong, which includes having meaningful, affectionate bonds from close relationships. Without such bonds humans are susceptible to psychological consequences, including negative affect and stress. Recently, research has begun to consider additional consequences of an unmet need to belong, including those impacting physiology, neurology, and physical health. Research employing animal models and human participants has provided converging evidence that social isolation is robustly and negatively associated with cognitive and cardiovascular function. In this review, we examine that evidence, review the possible mechanisms by which those associations form, and close by proposing avenues for future research to help elucidate these associations.