My eventual goal is to put these into categories of which articles address which ideas, and to give a quick summary of each, for easy perusal. Obviously, I’m not there yet.
Cold for depression
Adapted cold shower as a potential treatment for depression https://www.ncbi.nlm.nih.gov/pubmed/17993252 — This paper is actually one that’s often cited, but it isn’t an experiment. It’s one of those papers that builds a hypothesis about why something SHOULD work, in this case, cold water as a cure for depression. The authors did state that “Practical testing by a statistically insignificant number of people, who did not have sufficient symptoms to be diagnosed with depression, showed that the cold hydrotherapy can relieve depressive symptoms rather effectively.” While not super impressive as a conclusion, it was an interesting read.
Cold water swimming pretreatment reduces cognitive deficits in a rat model of traumatic brain injury https://www.ncbi.nlm.nih.gov/pubmed/28966648 This paper talks about how cold water exposure increases endothelial progenitor cells and angiogenesis in rats. Ok, grant you, it’s in rats, and why would you care anyway? Both of these things have links to lowered prevalence for depression and several illnesses that can predispose you to depression.
Scientific evidence-based effects of hydrotherapy on various systems of the body http://www.najms.org/article.asp?issn=1947-2714;year=2014;volume=6;issue=5;spage=199;epage=209;aulast=Mooventhan — This is a more general review of the body, and how it reacts to being thrown into water of a non-standard temperature.
The American Meteorological Society published research in 2011 that found current temperature has a bigger effect on our happiness than variables like wind speed and humidity, or even the average temperature over the course of a day. It also found that happiness is maximized at 57 degrees (13.9°C), so keep an eye on the weather forecast before heading outside for your 20 minutes of fresh air.