Thesis defense Ivana Buric (Donders series 473)
14 December 2020
Promotor: prof. dr. R. Kessels
Co-promotors: dr. I. Brazil, dr. M. Farias
Individual differences and psychobiological responses to mind-body interventions
There is considerable evidence for the effectiveness of mind-body interventions (MBIs) in improving mental and physical health in various clinical and non-clinical populations, but there are several gaps that remain poorly understood.
First, to understand molecular mechanisms of MBIs, we reviewed eighteen relevant studies that examined gene expression in the context of MBIs. Overall, the studies indicate that MBIs are associated with a downregulation of nuclear factor kappa B (NF-kB) pathway; this is the opposite of the effects of chronic stress on gene expression and suggests that MBI practices may lead to a reduced risk of inflammation-related diseases.
Second, to address the gap related to the effectiveness of MBIs on personality disorders, we recruited thirty participants who were prisoners with multiple personality disorders. They were assigned to a mindfulness intervention (n=10), to a yoga intervention (n=10), or to a wait-list control group (n=10). We expected that both yoga and mindfulness will improve self-regulation (i.e., executive attention, emotion regulation and self-awareness), reduce stress and risk-taking behaviour, downregulate inflammatory-related gene expression and increase alpha and theta power. By using intent-to-treat analysis, we found no significant effects of interventions on any of these measures (p>.05).
The third gap was related to individual differences in responding to meditation. The thesis synthesises heterogeneous evidence from previous studies that examined baseline participant variables that influence the response to meditation; first as a narrative review and then as a comprehensive meta-analysis.