A systematic review and meta-analysis of the effect of whole body cryotherapy on mental health problems

• Published in: Complementary therapies in medicine 2021-12, Vol.63, p.102783-102783, Article 102783
• Main Authors: Doets, Julia J.R., Topper, Maurice, Nugter, Annet M.
• Format: Article
• Language: English
• Subjects: Autoimmune diseases; Bias; Circadian rhythm; Cold; Cold therapy; Cooling; Cryotherapy; Cytokines; Data analysis; Depression - therapy; Exercise; Health problems; Heterogeneity; Humans; Immune system; Mental depression; Mental disorders; Mental Health; Mental health care; Meta-analysis; Outliers (statistics); Oxidative stress; Physical fitness; Physiology; Psychiatric somatic therapies; Quality of Life; Skin; Sleep; Statistical analysis; Subgroups; Systematic review; Treatment Outcome
• ISSN: 0965-2299; 1873-6963
• DOI: 10.1016/j.ctim.2021.102783

To give an overview of the nature and methodological quality of studies on whole body cryotherapy (WBC) as add-on intervention for mental health problems. A meta-analysis according to PRISMA guidelines was conducted (Prospero registration: CRD42020167443). Databases MEDLINE, PsycINFO and the Cochrane Library were searched. Risk of bias was scored according to the Cochrane ROBINS-I-tool to which an extra bias-dimension of allegiance bias was added. Within and between Hedges’ g pooled effect sizes were calculated for the main aspect of mental health measured. Treatment efficacy was examined using a random effects model. Heterogeneity was examined through identification of visual outliers and by I2 statistics. Out of 196 articles coming up from the search, ten studies met all inclusion criteria, six of which were (randomized) controlled trials. Together these studies report on a total of 294 participants receiving WBC. The within-group pooled effect size for mental health problems is large (Hedges’ g = 1.63, CI: 1.05-2.21), with high heterogeneity (I2 = 93%). Subgroup analyses on depressive symptoms and quality of life (QOL) showed a diminution of heterogeneity to moderate. Effect sizes for depressive symptoms are very large (Hedges’ g = 2.95, CI: 2.44-3.45) and for QOL medium (Hedges’ g = 0.70, CI: 0.15-1.24). The between-group pooled effect size is medium (Hedges’ g = 0.76, CI: 0.17-1.36). Results indicate preliminary evidence for WBC as efficacious add-on intervention for mental health problems, especially depressive symptoms. Further research in the form of RCTs with larger numbers of participants is needed. •In the professional world of sports whole body cryotherapy (WBC) has been used for some decades.•WBC leads to better exercise capacity, more regular circadian rhythm, improved quality of sleep and less tiredness in athletes.•Recently studies appeared which measured the effect of WBC on mental health. No meta-analysis was conducted on this subject yet.•Currently there is a lack of low-cost, easily accessible treatment possibilities for most psychiatric disorders.•This study shows that there is preliminary evidence for efficacy of WBC as an add-on intervention for mental health problems.