Summary: Yes, a technique called a cold water plunge can help mental health. In modern sports medicine, cold water therapy was designed to speed recovery after exercise and has a positive impact on a variety of physiological systems related to mental health and wellbeing.
Key Points:
- The practice of cold water immersion to improve health has been around since at least the 5th century B.C., mentioned by Hippocrates.
- In the modern era, cold therapy is known to reduce inflammation and improve recovery time from basic joint and muscle injury.
- In the early- and mid-20th century, mental health practitioners wrapped psychiatric patients in cold, wet, sheets for two opposing purposes: to soothe agitated patients, and to energize apathetic patients.
- In the late 20th century, mental health expert began using partial cold water immersion in dialectical behavior therapy (DBT) to reduce emotional reactivity.
What is a Cold Water Plunge?
A cold water plunge is an informal, colloquial term for cold water immersion therapy (CWI), which itself is a type of cryotherapy. Cold water plunge is often referred to simply as cold plunge. We’ll use all three terms interchangeably throughout this article.
Cold plunge, or cold water immersion (CWI), is exactly what it sounds like. Here’s a definition of cold water immersion, i.e. cold plunge, from expert authors on the topic:
“Cold water immersion refers to voluntarily exposing the entire body to cold water, with the temperature at or below 15° Celsius/59° Fahrenheit.”
We found that definition a study called “A Systematic Review and Meta-Analysis of The Effect of Whole Body Cryotherapy on Mental Health Problems.” The study authors reviewed the available literature on cold water immersion with the following goal:
“To give an overview of…studies on whole body cryotherapy (WBC) as add-on intervention for mental health problems.”
The research team conducted exhaustive methodological and statistical review of ten studies including close to three hundred participants. The most consequential of those studies, “Health Effects of Voluntary Exposure to Cold Water,” shows cold water immersion or cold plunge causes the following:
- Activation/reset of the sympathetic nervous system
- Secretion of various hormones including:
- Dopamine
- Epinephrine
- Norepinephrine
- Cortisol
Those hormones play a key role in how we respond to stress, regulate emotion, and process reward. Healthy levels of these hormones reflect stable and positive mental health, whereas dysregulation of these hormones is associated with the development of mental health disorders, poor distress tolerance, and low emotional regulation.
The same study shows that recreational cold water immersion or cold plunge improves aspects of physical health, including, but not limited to:
- Improved cardiovascular health
- Improved immune function
- Reduced inflammation
- Improved recovery from exercise
Those are the physiological systems in our bodies that benefit from cold plunge and cold water immersion therapy. Now let’s take a look at the mental health benefits.
How Cold Water Plunge Can Help Mental Health
The study examined whether a cold water plunge can help mental health outcomes, and reported the following. Patients who engaged in cold water therapy showed:
- Improved depressive symptoms
- Improved mood
- Increased energy
In addition, a study on cold water swimming (CWS) for depression showed engaging in CWS significantly improved scores – a 37 percent improvement – on the World Health Organization-Five Well-Being Index (WHO-5), and also showed significant improvement in sleep, with a 23 percent improvement on scores on the Pittsburgh Sleep Quality Index (PSQI).
Here’s how the study authors characterize these findings:
“[Cold therapy] showed a large effect from pre-treatment to post-treatment for all mental health problems it was used to support, with the greatest effect on depressive symptoms and overall quality of life.”
But how and why does taking a cold plunge help mental health?
The authors of the publication “Beyond the Cold Baths: Contemporary Applications of Cold-Water Immersion in the Treatment of Clinical Depression and Anxiety” conducted a review of the evidence and devised a theoretical template for how cold water therapy and/or cold plunge can help mental health. Here’s the stepwise process they propose:
- A person experiences negative emotional states, such as:
-
- Depression
- Anxiety
- A person voluntarily takes a cold plunge, i.e. immerses themselves in water colder than 60° for at least five minutes.
- The cold plunge elicits the following physical reactions:
-
- Activation of sympathetic nervous system
- Activates endogenous opioid system
- Increase noradrenaline
- Elevated β-endorphins
- Increase in dopamine
- Over time, these physiological responses elicit the following psychological response:
-
- Reduced impulsivity
- Reduced rumination
- Increased acceptance
- Increased cognitive reframing
- Improved self-efficacy
- Improved positive affect, i.e. mood.
- Those changes, in turn, can lead to the following mental health outcomes:
-
- Relief of anxiety symptoms
- Relief of depressive symptoms
Those are the proposed mechanisms by which a cold plunge can help mental health. These proposed pathways give weight to the summary conclusion reached by the authors meta-analysis we review in he previous section:
“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.”
That research is ongoing, and yields more and more encouraging results each year. We’ll close this article with a recent examination of how cold water plunge affects wellbeing in healthy individuals.
Additional Evidence for the Impact of Cold Plunge on Mental Health
In the study “Cold Water Immersion: Exploring the Effects on Well-Being – Scoping Review,” a group of researchers designed a study they describe as follows:
“Cold-water immersion (CWI) has gained popularity in recent years due to its potential health benefits. This scoping review aimed to investigate the qualitative benefits of CWI through the experiences of healthy individuals”
In the review, researchers examined a total of 13 studies that examined whether cold water plunge can help mental health and overall wellbeing in people with no significant health problems. They identified four (4) distinct themes that reflected the qualitative – i.e. the subjective – experience of CWI on the participants.
Participants reported CWI, or cold water plunge, yielded mental health and wellbeing benefits associated with the following:
1. Physical and psychological health:
- Improvements in both these areas promote positive mental health and wellness
2. Exposure to nature:
- Direct experience of the outdoor world improves self-esteem and self-efficacy, both associated with positive mental health.
3. Sense of connectedness:
- Connection to friends, family, and the immediate community is a protective factor for menta health.
4. Personal growth:
- The ability to learn and apply new skills, increase and expand individual awareness of the world, and improve knowledge about overall physical and mental health can contribute to improved overall wellbeing.
The study authors characterize these insights as follows:
“The experiences individuals gain from CWI are profound and can exert both direct and indirect influences on the promotion of well-being. Participating in CWI shows significant promise as a means to enhance wellbeing.”
The impact of cold plunge can vary by the individual. In many cases, people are apprehensive about taking the plunge, but after the initial shock of cold fades and they experience what it’s like to spend time immersed in cold water, and how they feel an hour later – and even later in the day – many look forward to the experience.
We see it happen every day: when people experience the personal, subjective benefits, many move quickly from reluctance to anticipation, and consider cold plunge an essential component of treatment success.
