predicted an increased likelihood of

predicted an increased likelihood of becoming inactive, but the effects of loneliness were independent of changes in health status. Similarly, individuals with fewer social connections (i.e., a smaller social network) were less likely to be physically active, but the effects of loneliness on physical activity did not depend on the size of the social network. The invisible force of loneliness seems to play a unique role in this particular predisease pathway. Another commonly cited risk factor for disease is stress. In reality, “stress” refers to a family of predisease pathways, each of which may be vulnerable to the influence of lonely feelings. Loneliness is itself a source of stress, but lonely individuals also differ in their exposure to stressful events and circumstances. This is less evident in young adults than it is in older adults in whom loneliness was associated with having experienced a greater number of stressful life events in the past year (e.g., death in the family, marital crisis, change in employment status) and more sources of chronic stress (e.g., employment stress, marital stress).° In addition, lonely individuals perceive life as more stressful and less gratifying than their socially connected counterparts, even when objective indications are that lonely and nonlonely individuals do not differ in the types of activities and behaviors they engage in on a daily basis. Good quality social interactions typically ameliorate feelings of stress, but because lonely people perceive their interactions to be less positive than those of nonlonely people, they fail to derive the same benefit. Good coping strategies can also ameliorate feelings of stress, but lonely individuals are more likely to respond to stress with pessimism and avoidance than with optimism and active Page |43 engagement. And to add insult to injury, loneliness increases sensitivity to and surveillance for social threats. Anxiety, low self-esteem, and fear of negative evaluation elicit self-defensive behaviors and effectively tax cognitive resources that would normally be available to meet the demands of daily life stress. Thus, what might naively be thought of as a circumscribed problem—the feeling of loneliness and isolation—may be seen by the sufferer as a world of inescapable threat.’ How might these cognitions and perceptions influence physiology and health? As Berntson shows in his chapter, the brain regions involved in emotional and perceptual processes are intimately related to brain regions involved in the regulation of physiological systems. This is particularly evident in alterations of the functioning of the cardiovascular system in lonely individuals. In young adults, this alteration is apparent in increased resistance to blood flow in small arteries throughout the body. Increased vascular resistance is a precursor and predominant contributor to age-related increases in systolic blood pressure (SBP), a major risk factor for cardiovascular disease. In middle-aged adults, SBP is significantly higher in lonely adults than in their nonlonely counterparts. Moreover, loneliness accelerates the rate of increases in SBP,* indicating a faster decline in physiological resilience and a heightened risk for chronic cardiovascular disease. It’s as though loneliness accelerates the aging process. By virtue of extensive interconnections among the brain, peripheral nervous systems, and endocrine glands, the feelings of isolation and loneliness have a broad and HOUSE_OVERSIGHT_021289