A standout
Regarding the effect of the type of intervention on the association, only CBT (31 studies; P < .001) and multiple or combined interventions (seven studies; P = .01) were significantly associated with changes in immune system outcomes.
The analysis also found that interventions that included a group component were more consistently associated with enhanced immune function than were those that did not include a group component. Nevertheless, this difference did not reach statistical significance (P = .06).
Contrary to the researchers’ expectations, the analysis also revealed that intervention length did not moderate the association between psychosocial interventions and immune system function (P = .93).
With respect to the type of immune marker studied, the meta-analysis found that psychosocial interventions had significantly different associations with the various immune markers studied. Of the seven immune outcomes investigated, only proinflammatory cytokine or marker levels (33 studies; P < .001) and immune cell counts (27 studies; P < .001) were significantly associated with the psychosocial interventions examined.
and were robust across age, sex, and intervention duration.
These results suggest that psychosocial interventions – particularly CBT and multiple or combined psychotherapeutic modalities – may play an important role in improving immune-related health outcomes.
Such interventions may not only be effective, they may also prove to be affordable alternatives to current therapeutic options. The mean length of a CBT intervention in the meta-analysis was 10.4 weeks, which the investigators equated with a total cost of $1,560 per patient.
“By comparison, the cost of using infliximab to reduce inflammation in persons with an autoimmune disorder is approximately $25,000 per patient per year,” they wrote.
“The results suggest the possibility that psychotherapy may be helpful for reducing inflammation and improving immune-related health in certain circumstances,” Dr. Slavich concluded. “However, the studies that we examined differed in terms of their quality, and we did not examine health outcomes in the present investigation.
“Therefore, more research needs to be done to determine how the present findings might be translated into treatment options or public policy.”
A path to better health
In an accompanying editorial, Veronika Engert, PhD, Joshua A. Grant, PhD, and Bernhard Strauss, PhD, noted that although infectious disease was once the primary cause of death in society, it has been supplanted by other complex and chronic illnesses, which often do not follow simple cause-and-effect associations.
“Rather,” they wrote, “these illnesses develop from a complex milieu of biological, psychological, and social factors that may also influence the disease progress and its prognosis. Against this backdrop, the meta-analysis by Shields and colleagues is an important confirmation of the biopsychosocial model.”
The editorialists explained that recent psychophysiological, neurobiological, and epigenetic research offers a glimpse into the relationship between psychological and social factors in pathogenesis. Nevertheless, the authors noted that a comprehensive examination of the potential effects of psychosocial interventions on immune parameters in various physical health conditions has been lacking.
“The evidence provided by Shields et al. is exactly what is needed to more fully shift treatment from an illness-centered to a patient-centered approach,” they wrote. “To that end, this meta-analysis may serve as a guide for policy makers aiming to improve immune-associated health.”
The research was supported by a Society in Science–Branco Weiss Fellowship, Brain and Behavior Research, and the National Institutes of Health. Dr. Slavich, Dr. Engert, Dr. Grant, and Dr. Strauss have disclosed no relevant financial relationships.
A version of this article originally appeared on Medscape.com.