Dysfunction of the stress response system, particularly the autonomic nervous system, may be one mechanism underlying persistent physical symptoms that are not fully explained by biomedical factors. Vreijling et al. conducted a meta-analysis of studies investigating heart rate variability indices of parasympathetic activity (including 22 studies examining root mean square of successive differences [RMSSD] and 52 examining high-frequency heart rate variability [HF-HRV]) in syndrome clusters of persistent physical symptoms, including fibromyalgia, irritable bowel syndrome, and chronic fatigue syndrome. Individuals with these conditions had lower RMSSD and HF-HRV than individuals without persistent physical symptoms. Reduced parasympathetic activity may therefore play a role in patients with these conditions.
In a large multi-ethnic cohort study by van Nieuwenhuizen et al. the association between socioeconomic status (as indicated by education and occupation) and sympathovagal balance of the autonomic nervous system was assessed. Using two measures of sympathovagal balance (heart rate variability and baroreflex sensitivity), the results indicated that low socioeconomic status was associated with lower heart rate variability and reduced baroreflex sensitivity in the Dutch majority population. These associations were also found, but less strong, in most of the ethnic minority groups. The findings suggest that sympathovagal dysregulation may play a role in health disparities in cardiovascular disease and other adverse health outcomes.
Implicit affect represents the automatic, pre-reflective appraisal process involved in conscious emotional experiences. Greater implicit negative affect is associated with larger physiological stress responses. Low heart rate variability (HRV) may increase the impact of implicit negative affect on health. Gouin et al. report that high implicit negative affect is associated with the metabolic syndrome among individuals with lower HRV. Similar associations were observed with the lipid accumulation product, a measure of central lipid accumulation based on waist circumference and triglycerides. The present findings highlight the relevance of including implicit affect measures in psychosomatic medicine research.
Placebo interventions can have positive effects on symptoms and health outcomes. Recent evidence suggests that interventions that do not conceal the non-active nature of a placebo (“open label placebo”) may still produce positive placebo effects. In an evoked-itch experiment, Meeuwis et al. investigated whether positive and negative verbal suggestions could influence expectations and subsequently elicit placebo and nocebo effects. In healthy participants who received positive suggestions, itch was reduced regardless of whether they knew they had received the placebo (open label) or did not know (closed label) compared to those who received negative suggestions. Open-label suggestions may be a new tool to employ placebo effects in clinical practice, for example, by explaining the role of expectations in treatment.
Another article in this issue explores the role of expectations as determinants of placebo and nocebo phenomena. Verbal information can shape expectations in terms of magnitude and direction of these effects. Camerone et al. demonstrate that suggestions about when a treatment effect might occur can be used to modulate the onset of action of a given (inert) treatment. These findings could open new ways to optimize treatment outcomes in conditions where “side effects” or toxic effects of pharmacotherapy are common, but further investigation is needed to better understand the nature and temporal role of expectations.
The stress-buffering hypothesis states that social support is beneficial for health only or particularly for those individuals reporting high levels of stress. Chen et al. tested the interactive effects of social support and stressful life events on children’s cortisol and salivary alpha amylase responses to a controlled stress-inducing challenge task. Children reporting high numbers of stressful life events and low perceived social support exhibited the lowest post-stressor peak cortisol levels and flattest cortisol recovery slopes. In contrast, children high in stressful life events and high in social support displayed cortisol response profiles more similar to those of children with low stressful life events.
Niedhammer et al. investigated the prospective associations between psychosocial work factors of the job-strain model and all-cause mortality. Low decision latitude, low social support, job strain, isostrain (the combination of job strain and low social support), high strain, and passive job conditions (low levels of demands and decision latitude) were found to be risk factors for mortality. Results suggested that current or more recent exposure may be more important than past exposure. Interventions to improve the psychosocial work environment may help to prevent mortality in working populations.
Suboptimal levels of self-care among individuals with diabetes mellitus (DM) are a significant public health concern. In a randomized control trial, Chan et al. used the Common Sense Model (CSM), which proposes that patients’ illness representations—their interpretations of information and experiences—are associated with coping and health outcomes across various conditions. The CSM-based intervention was found to be effective in improving self-care and coping among patients with DM.
Pages 71–84; http://doi.org/10.1097/PSY.0000000000000883
Rosson et al. conducted a large-scale meta-analysis investigating the prevalence and trajectories of depressive, anxiety, and post-traumatic stress disorder (PTSD) symptoms in patients with cardiac disease after undergoing heart surgery. Evidence showed that anxiety symptoms improved for one year after heart surgery, whereas PTSD symptoms might worsen. Subgroups of older patients and those with metabolic comorbidities, valve disease, or ventricular arrhythmias were at higher risk for continued depressive and anxiety symptoms and should be monitored more closely.
Pages 85–93; http://doi.org/10.1097/PSY.0000000000000872
Expectations play a role in the predictive processing of somatic symptoms. Wolters et al. investigated the effects of a sham exposure to electromagnetic field radiation when conducting a tactile detection task. Ostensible exposure led to a more liberal response criterion and thus a higher propensity to experience somatosensory illusions in a healthy sample. This shift in somatosensory bias through expectation contributes to the understanding of somatic symptom disorder and supports the predictive processing theory of somatic symptom generation.
Pages 94–100; http://doi.org/10.1097/PSY.0000000000000884