Mind and body exercises : associations with mental health, antidepressant medication, autonomic functioning and inflammatory biomarkers

Abstract

Stress, depression and stress-related mental ill-health are common in societies all over the world, and people tend to use both conventional care within the health care system and complementary treatment methods to handle the related symptoms. Still, there is sparse information on whether, how and when to combine these different treatment modalities, in spite of their relatively widespread use. There is thus a need for increased knowledge on complementary treatment methods among conventional health care professionals, patients, policy- and decision makers, and the general public. An example of complementary methods is so called mind and body exercises (MBE), which include e.g. mindfulness based interventions (MBIs).

Aims: The overall aim of this thesis was to map the use of MBE and its associations with health and markers of disease, i.e. prescriptions of psychotropics, and to study if there are any robust effects of MBIs on biomarkers of stress. The findings were thus aimed to enable evidence-based recommendations and personalized treatment strategies. The specific aims were: To identify differential associations regarding gender, age, socioeconomic status, health behaviors, perceived stress, self-rated health, and the purchase of prescribed drugs among people who practice MBE extensively, compared to people who do not practice MBE (study I); To further investigate the temporal relationship between MBE, depressive symptoms, purchase of antidepressant drugs and physical exercise, based on the cross-sectional findings in study I (study II); To evaluate existing data on the effect of standardized mindfulness based interventions on inflammatory biomarkers and autonomic nervous system functioning (assessed by measurements of heart rate variability, HRV), through a systematic review and meta-analysis (study III); To investigate the effects of a Mindfulness Based Childbirth and Parenting intervention on HRV and serum inflammatory marker levels among pregnant women, through an RCT study with an active control group comparison (study IV).

Methods: Studies I and II were based on responses from the Swedish Longitudinal Occupational Survey of Health (SLOSH). Measures regarding MBE practice, health behaviors, perceived stress, self-rated health and illnesses were drawn from the SLOSH questionnaire, while data on antidepressant drug purchase for all respondents was obtained from the Swedish Prescribed Drug Register. In study III, a literature search was conducted in collaboration with two experienced university librarians. Literature screening and data extraction were performed independently by two researchers. The methodological quality of included studies was assessed independently by two researchers using the Cochrane Collaboration’s tool for assessing risk of bias. In study IV, first time pregnant women at risk of perinatal depression were randomized to MBCP or an active control treatment. At baseline and post-intervention, participants filled out questionnaires and measures on HRV and inflammatory biomarkers were collected.

Results: MBE practice was found to have significant cross-sectional associations with high levels of depressive symptoms and prescribed antidepressant purchases (study I). The temporal investigations of these relationships revealed a more complex picture, where MBE practice itself was not associated with either subsequent antidepressant medication or with subsequent depressive symptoms (study II). No significant effect of standardized MBIs on inflammatory biomarkers or HRV, when compared to active controls, treatment as usual or wait-list controls, was found – neither in the meta-analysis (study III) nor in the randomized controlled study (study IV).

Conclusions: The findings from study I and II demonstrate the use MBE among the general population as well as in clinical populations like patients suffering from mental ill-health. In order to gain a deeper understanding of the temporality of these correlations, and to delineate possible beneficial or harmful combinations of psychotropics, MBE and other treatment strategies, further research is needed. The findings from study III and IV highlight the necessity of larger, more rigorously conducted RCTs with standardized MBIs being compared to various forms of active controls, also including more long-term follow-ups, in order to provide evidence-based recommendations, both for self-help use and clinical practices.