Naturalistically observed sighing and depression in rheumatoid arthritis patients: a preliminary study.

Rheumatoid arthritis (RA) is a chronic systemic inflammatory disorder characterized by pain and destruction of peripheral joints. As with physical health, RA exacts a heavy toll on mental health. About forty percent of RA patients develop comorbid depression (Covic, Tyson, Spencer, & Howe, 2006), which tends to exacerbate disease activity and undermine health-related quality of life (Zautra et al., 2004). Because depression most immediately affects people’s inner mood and cognitive landscape, it is often “invisible” to outsiders. Thus, depression’s privacy can impede its early detection and thereby adequate treatment. These issues are compounded when the social stigma surrounding depression leads to patients intentionally hiding symptoms (NIMH, 2001). Therefore, identifying observable, behavioral markers of depression is an important scientific endeavor with theoretical and clinical implications (Mehl, 2006). This study sought to identify such an observable, behavioral marker of depression in RA patients. To focus on behavior that is accessible to outside observers, we employed a novel naturalistic observation sampling methodology, the Electronically Activated Recorder (EAR; Mehl, Pennebaker, Crow, Dabbs, & Price, 2001). The EAR is a digital audio recorder that periodically samples brief snippets of ambient sounds from participants’ momentary environments. Participants wear the EAR while going about their lives, providing an “acoustic log” of their days as they naturally unfold. Sighing is a behavior that has been phenomenologically defined as “an obvious exaggerated exhalation of breath” (p. 366; Keefe & Block, 1982), and physiologically as a breath that is “at least 500 mL larger than the mean of the prior three breaths and at least 400 mL larger than the following breath” (Abelson et al., 2001; p. 589). As such, sighing is a subtle expression that is potentially detectable by the EAR. Despite its intuitive tie to constructs such as psychological distress and depression, it has so far received very little scientific attention. The scarce research that exists on sighing suggests that it is conceptually and empirically linked to negative affect (Roth, 2005; Wilhelm, Trabert, & Roth, 2001). Empirically, in-lab studies have found that panic disorder patients sigh significantly more often than control participants (e.g. Abelson, Weg, Nesse, & Curtis, 2001; Wilhelm et al., 2001), suggesting that sighing may be an indicator of anxiety. Further, in research with chronic pain patients, sighing is often used as a pain behavior. For example, Keefe and Block (1982) found spontaneous sighing during a physical exam to be correlated with pain ratings. Finally, Teigen (2008) found that healthy participants sighed frequently during a difficult or impossible in-lab task. The scarcity of research on sighing seems partly due to methodological challenges surrounding its assessment. Global and retrospective self-reports asking participants to report how often they sigh are problematic given that people tend to be unaware of when and how much they sigh (Teigen, 2008). Even ecological momentary assessments (Ebner-Priemer & Trull, 2009; Conner et al., 2006) struggle in the case of sighing, as the act of monitoring and reporting sighs can reactively affect its measurement and undermine its validity (e.g. via inducing self-awareness). The EAR allows for an unobtrusive observational assessment of subtle and highly automatic behaviors, such as sighing, in their natural ecological context (Mehl, Vazire, Holleran, & Clark, 2010; Mehl, Vazire, Ramirez-Esparza, Slatcher, & Pennebaker, 2007). The present study tested whether sighing is an observable marker of depression in RA patients. Participants wore the EAR for two weekends separated by one month. The frequency with which they sighed in their daily lives was determined from the sampled ambient sounds. Depression and physical symptoms were assessed with self-reports. Specifically, the study addressed the following research questions: (1) To what extent is sighing related to depression? Consistent with the notion that sighing expresses negative affect (Wilhelm et al., 2001), we predicted that sighing would be positively related to depression. (2) To what extent is sighing related to the experience of physical symptoms? Based on prior research with chronic pain patients (Keefe & Block, 1982), we predicted that sighing would be positively related to physical symptoms.