Physiological stress markers, mental health and objective physical function.

Area of Science:

• Psychoneuroimmunology
• Physiology
• Mental Health Research

Background:

• Poorer physical function is observed in individuals with mental disorders.
• Dysregulation in physiological stress systems may contribute to this poorer physical function.
• An integrated understanding of stress systems' role in objective physical function is lacking.

Purpose of the Study:

• To examine the association between multiple physiological stress systems and objective physical function.
• To explore if these stress systems mediate the relationship between depression/anxiety and poorer physical function.

Main Methods:

• Utilized data from 2860 participants in the Netherlands Study of Depression and Anxiety.
• Assessed physical function via hand grip strength and lung function (peak flow meter).
• Measured inflammatory markers (CRP, IL-6, TNF-α), salivary cortisol, and autonomic nervous system (ANS) markers.

Main Results:

• Higher inflammation correlated with lower hand grip strength and lung function.
• Elevated evening cortisol levels were associated with reduced lung function.
• The link between depression/anxiety and poorer physical function in women was not significantly reduced by stress markers.

Conclusions:

• Stress system dysfunction, particularly immune-inflammatory and HPA-axis, contributes to poorer objective physical function.
• Stress system dysfunction does not account for the poorer physical function in individuals with depression/anxiety disorders.
• Other pathways likely explain the association between mental disorders and reduced physical function.