Mindfulness-Based Interventions and the Hypothalamic-Pituitary-Adrenal Axis: A Systematic Review.

Area of Science:

• Psychoneuroendocrinology
• Behavioral Medicine
• Stress Research

Background:

• Mindfulness-based interventions (MBIs) are explored for their impact on health outcomes.
• Cortisol levels serve as a key biomarker for assessing an individual's stress state.
• MBIs are hypothesized to influence physiological stress markers, including cortisol.

Purpose of the Study:

• To systematically review and synthesize existing research on the effects of MBIs on cortisol levels.
• To analyze studies evaluating the relationship between mindfulness practices and cortisol regulation.

Main Methods:

• A comprehensive literature search was conducted across multiple databases (e.g., PubMed, Scopus, Web of Science) from January 1990 to May 2024.
• Studies were included if they featured intervention and control groups, with rigorous screening using the JBI Critical Appraisal Checklist.
• Search terms included "mindfulness", "mindfulness-based interventions", and "cortisol".

Main Results:

• Twenty-five studies reported significant changes in cortisol levels following MBIs, while ten found no significant alterations.
• Common limitations identified across studies include small sample sizes, lack of randomization, absence of blinding, and potential confounding variables.

Conclusions:

• While MBIs possess biological plausibility for influencing cortisol, the current evidence base is weakened by methodological limitations.
• Establishing a definitive causal link between MBIs and cortisol level changes requires more robust, well-designed research.