Loneliness, daily pain, and perceptions of interpersonal events in adults with fibromyalgia.

Individuals who are isolated from others are at risk for poorer health (Shankar, McMunn, Banks, & Steptoe, 2011). Objective markers of social isolation have included small social network size, reports of little social contact, and living alone. Independent of objective social isolation, individuals may also have a subjective experience of social isolation and disconnection, or loneliness. Loneliness is the feeling that one is isolated from the interpersonal intimacy and relationships one desires (Cacioppo et al., 2002; Peplau & Perlman, 2000; Shankar et al., 2011). Measures of objective social isolation and loneliness are only weakly related (Shankar et al., 2011). Indeed, loneliness ratings are only modestly related to indicators of social network size and frequency of interaction with network members (Hawkley, Masi, Berry, & Cacioppo, 2006), and only share approximately 50% of the variance with ratings of availability of support from the social network (e.g., Cacioppo, Hughes, Waite, Hawkley, & Thisted, 2006). Thus, the extant data indicate that loneliness represents the subjective, emotional experience of being socially isolated, distinct from objective markers of social isolation and lack of social support. Similar to objective social isolation, loneliness has been linked with risk for poor health. The bulk of research in this area has examined whether longstanding feelings of loneliness are a risk factor for health problems. Chronic loneliness has been linked with negative consequences for psychological health, including increased risk for depression, and for physical health, including increased stress-related inflammation, sleep disturbance, poorer immune functioning, and elevated cardiovascular risk (Cacioppo, Hawkley, & Thisted, 2010; Jaremka et al., 2013; Hawkley & Cacioppo, 2007; Hawkley & Cacioppo, 2010). Further, chronic loneliness significantly predicts subsequent physical and emotional health, even when accounting for depression and social support (Cacioppo et al., 2010; Cacioppo et al., 2006). Although loneliness has trait-like elements, it can also be a transitory experience with links to markers of daily functioning. For example, day-to-day and within-day fluctuations in loneliness have been related to deleterious changes in the stress response, especially under conditions of high interpersonal stress (Adam, Hawkley, Kudielka, & Cacioppo, 2006; Doane & Adam, 2010). In both young and older adults, higher feelings of loneliness on one day were associated with an increased cortisol awakening response on the following morning, a hormonal response pattern linked to elevated stress (Doane & Adam, 2010, Adam et al., 2006). Individuals with high versus low chronic interpersonal stress were especially vulnerable to the negative effects of episodes of loneliness, showing greater loneliness-induced increases in cortisol (Doane & Adam, 2010). Beyond its physiological effects, one day’s increase in loneliness has been associated with increases in the next day’s symptoms, including exhaustion and fatigue, over and above the influence of the prior day’s depressed affect and sleep duration (Hawkley, Preacher, & Cacioppo, 2010). Taken together, the available evidence indicates that both chronic loneliness and daily fluctuations in loneliness predict emotional and physical health. The majority of investigations of loneliness and its repercussions have examined the impact of loneliness in physically healthy individuals. However, a small but growing body of evidence has linked loneliness to the experience of bodily pain, one of the most common and costly medical problems in the United States (Gaskin & Richard, 2012). Among breast cancer survivors, for example, chronic loneliness is associated with higher levels of pain, depression, and fatigue (Jaremka et al., 2012). Similarly, older adults with chronic pain report being significantly more lonely than do those without pain (Jacobs, Hammerman-Rozenberg, Cohen, & Stessman, 2006; Tse, Leung, & Ho, 2012). Moreover, loneliness predicts more than a four-fold increase in the prevalence of chronic pain among elderly individuals over time (Jacobs et al., 2006). Some intriguing evidence also points to a potential link between state loneliness and pain. In fact, episodes of physical pain and the perceived social exclusion that characterizes loneliness activate common brain circuits (Cacioppo, Norris, Decety, Monteleone, & Nusbaum, 2008), indicating that there may be a “pain signature” in the central nervous system that is activated by both physical and social stimuli (Eisenberger, Lieberman, & Williams, 2003; Wager et al., 2013). To the extent that loneliness shares common underlying neurophysiological circuitry with physical pain, acute increases in loneliness may increase vulnerability to physical pain (Eisenberger & Lieberman, 2004). Given the links between chronic and state loneliness and pain, the experience of loneliness may have implications for adaptation among individuals managing a chronic pain condition. How might loneliness impact their adaptation? One possibility is through its impact on appraisals of social interactions. Lonely people have more negative perceptions of the quality of social interactions in their daily lives compared to their nonlonely counterparts, which seems to perpetuate a cycle of social disconnection (Hawkley, Preacher, & Cacioppo, 2007). Such social withdrawal may both increase their experience of interpersonal stress and limit their capacity to draw on positive social engagement, an important resource to sustain quality of life among people with chronic pain (Finan et al., 2010; Potter, Zautra, & Reich, 2000; Skinner, Zautra, & Reich, 2004). Thus, among individuals with chronic pain, loneliness may impair the capacity to effectively limit negative social contacts and draw on positive social resources to sustain healthy functioning. Because much of the work tying loneliness and health has focused on the impact of chronic elevations in loneliness, the impact of short-term, day-to-day fluctuations in loneliness on the physical and emotional health of those with chronic pain is largely unknown. To address this gap in the literature, the current study drew on daily diary reports of individuals living with fibromyalgia (FM) to examine the links between loneliness, interpersonal experiences, and pain. FM is a prevalent condition that is characterized by widespread pain and fatigue of unknown origin (Wolfe et al., 1990). Co-morbid mood disturbance is common; anxiety and mood disorders have been reported by as many as 75% of individuals with FM (Thieme, Turk, & Flor, 2004). Moreover, persons with FM show deficits in positive affect (Finan, Zautra, & Davis, 2009) and report poor quality social ties (Schoofs, Bambini, Ronning, Bielak, & Woehl, 2004). Especially relevant for the current work, individuals with FM often feel alienated and isolated because the credibility of their illness as well as their personal integrity are often called into question by others (Asbring & Narvanen, 2002). Those who experience that social isolation due to their FM report withdrawing from social situations as a strategy to avoid potential stressors (Asbring & Narvanen, 2002). The current study examined whether chronic levels of loneliness and/or daily fluctuations in loneliness among individuals with FM relate to 1) exposure to positive and negative interpersonal events, and 2) responses to day-to-day changes in interpersonal events in terms of event appraisals and pain. In line with the limited extant evidence, it was expected that elevated chronic and state loneliness would both be associated with higher pain levels, a more deleterious social milieu, and more maladaptive responses to interpersonal events, and that these effects would be evident even when accounting for daily depressive symptoms.