Cold Water Exposure and Mental Health – Protocol of a New Systematic Review (02.06.2025)

Schepanski S., Batta F., Schröter M., Seifert G. and Koch, A.K. (2025)
Protocol for a systematic review and meta-analysis on the effects of cold-water exposure on mental health.
Front. Psychiatry 16:1603700. doi: 10.3389/fpsyt.2025.1603700

The practice of cold-water exposure (CWE) has a long tradition in hydrotherapy. While reports and media suggest various benefits for well-being, the scientific evidence so far remains fragmented. To close this gap, a research team at Charité Berlin has published a protocol for a systematic review and a meta-analysis.

The aim of the study
The planned study aims to critically assess and synthesize the available evidence on the effects of CWE on mental health in adults. Both healthy individuals as well as those with clinical diagnoses are taken into account.

Examined Mechanisms and Indicators
The analysis will focus on two central areas:

• Psychological variables: These primarily include symptoms of depression and anxiety, the subjective perception of stress, as well as overall mental well-being.

• Physiological stress markers: Among other things, neurobiological markers such as cortisol and norepinephrine, heart rate variability (HRV), and inflammatory cytokines (e.g., IL-6 or TNF-α) are examined.

Scientific Background
Physiologically, cold water activates multiple systems, including the autonomic nervous system and the hypothalamic-pituitary-adrenal axis (HPA axis). Researchers are following the hypothesis that repeated cold exposure can lead to adaptive processes that improve stress resilience. In addition, psychological mechanisms such as increased self-efficacy from overcoming the initial cold stimulus could play a role.

Results

The systematic review bridges the gap between anecdotal claims and scientific evidence regarding the mental effects of cold water exposure (CWE). It serves as a basis for evidence-based practice guidelines in the wellness and clinical fields, as well as for future public health strategies, while also taking physiological risks (e.g., cold shock) into account.

The protocol for this review on the effects of cold water exposure on mental health can be found here in English (click button).