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Sensory Deprivation Tank Science: How ‘Floating’ Works & Proven Benefits

By Jillian Levy, CHHC

September 19, 2021

Original article and page source found here.

Sensory deprivation tank float centers are popping up all over the United States and Europe, especially in urban areas where the demand for holistic healing surges. According to annual official Float Tank Industry reports, the U.S. was home to more than 300 float centers in 2015, up from about 85 in 2011, and the trend continues to grow.

Whether referred to as sensory deprivation tanks, float tanks or simply as “floating,” deprivation therapy treatments have earned a reputation for naturally easing many ailments.

Floaters report sensory deprivation tank benefits that include reduced insomnia, anxiety and depression, plus relief from chronic pain and even addictions. The beauty in all of this: These reported benefits are possible without a doctor’s visit, breaking a sweat or filling any prescriptions.

What Is a Sensory Deprivation Tank?

Sensory deprivation is achieved through floating in a type of isolation tank that cuts off all sources of sensory experience: sound, sight, smell and touch.

Another way that floating is referred to in research studies is “restricted environmental stimulation technique,” or floating-REST.

What does floating in a deprivation tank do — or feel like? Proponents of floating told the the New York Times that a session can make you practically feel like an astronaut, saying “it’s something you can never experience otherwise.”

Float tanks (or sensory deprivation chambers) that are used for inducing sensory deprivation are filled with water that is almost the exact same temperature as the floater’s body, along with high amounts of Epsom salt (made from magnesium sulphate). The salts allow you to remain restfully floating at the water’s surface in complete silence and stillness.

During the entire session, floaters generally feel light and peaceful, without needing to exert any effort to stay afloat.

What are sensory deprivation tanks used for? As you’ll learn below, the main purpose of flotation-REST is eliciting a positive effect on physiology, including lowering levels of cortisol, reducing blood pressure and promoting positive feelings of well-being.

Studies show that increased mindfulness and decreased stress during float session reduce markers of bodily distress syndrome (BDS), aka symptoms caused by chronic stress. Researchers often use the term “BDS” to describe negative physiological changes that take place when someone is under a lot of stress. These BDS signs are now tied to things like fibromyalgia symptoms, chronic fatigue syndrome and somatization disorder.

History of Floating:

Although the benefits of float tanks only recently garnered lots of buzz, they’ve actually been around since the 1950s and used in Europe on and off since the ’70s.

At the time of sensory deprivation tank creation, psychoanalytic researchers and neuroscientists used the tanks mainly to test effects on things like creativity, connection to others and concentration.

Some report that float tanks can actually bring about a “psychedelic experience.” Over the last few decades, esoteric communities promote floating as a way to promote “spiritual awakeness,” emotional breakthroughs and enhanced clarity of mind.

While these benefits are difficult to prove, research published in the Journal of Complementary & Behavioral Medicine now suggests that sensory deprivation may actually work by reducing the body’s stress response, inducing deep relaxation and quieting mental chatter.

A slew of research now shows that “floatation therapy” is an effective, noninvasive method for treating stress-related illnesses and pain, more so than a placebo or even many other methods currently used in complementary medicine.


1. More ‘Mindfulness’ and Reduced Stress

The 2014 Journal of Complementary & Behavioral Medicine study mentioned above, which tested the effects of sensory deprivation on markers of quality of life in 65 adult patients as part of a cooperative health project, found a significant correlation between “altered states of consciousness during the relaxation in the flotation tank” and “mindfulness in daily life.”

Scientists randomized study participants to either a wait list control group or a flotation tank treatment group. The sensory deprivation tank group participated in a seven-week flotation program, consisting of a total of 12 float sessions.

After being tested for measures of psychological and physiological well-being — including variables like stress, energy, depression, anxiety, optimism, pain, sleep quality and mindfulness — results showed significant reductions in:

  • Stress responses

  • Depression symptoms

  • Anxiety

  • Pain

Scientists also observed improvements in general optimism, sleep quality and “mindful presence” (or awareness) during the study.

2. Reduced Anxiety and Depression

In 2016, researchers from the Department of Psychology at Karlstad University in Sweden tested the effects of sensory deprivation tank floating on symptoms of anxiety disorders, including general anxiety disorder (GAD), which remains one of the most challenging mental health problems to treat. Study findings showed that GAD symptomatology significantly changed for the better for the 12-session float group over a four-month period.

In fact, 37 percent of participants in the float-treatment group reached full remission from GAD symptoms at post-treatment, while the majority experienced at least some significant beneficial effects related to sleep difficulties, problems with emotional regulation and depression. All improved outcome variables at post-treatment, except for certain symptoms of depression, remained at the six-month follow-up point after the study. No negative effects surfaced in the floaters.

3. Improved Energy and Work Productivity

Stress-related illnesses now top the most common reasons for reduced productivity at work, employees using sick days, lost sleep and employee fatigue. Problems attributed to stress include mental fatigue (also called “brain fog“), lack of concentration, burnout syndrome, migraines or tension headaches, and digestive or gastric complaints.

Facing these daunting stats, more employers are offering complimentary floating sessions or similar approaches, like breaks for meditation, in order to keep stress levels low.

While stress reduction is a common doctor’s recommendation for patients who are already dealing with these problems, it seems to be most helpful when stress is prevented or managed before it reaches damaging levels. There’s evidence that sensory deprivation floating is now considered a cost-effective, natural and helpful stress-preventative method for decreasing potential sick-leave absences and increasing general well-being in the workplace.

4. Less Pain

Several studies, as well as patient testimonials, suggest float tanks could serve as natural painkillers. The primary way that floating helps ease pain is through evoking a relaxation response, which eases tense muscles and helps improve rest and recovery.

One study examining the effects of placebo treatments versus flotation tank therapy found that floating sessions reduced stress-related muscular pain in patients diagnosed with “burnout depression.”

The patients treated with this flotation-restricted environmental stimulation technique for six to 12 weeks exhibited less pain, lower blood pressure levels, less anxiety and depression, reduced feelings of stress and negativity, and increased happiness/optimism, energy and positive affectivity.

5. Help Overcoming Addictions

A study from the ’90s aimed at identifying the effectiveness of sensory deprivation on reducing addiction found that “REST is a versatile, cost-effective treatment modality with demonstrated effectiveness in modifying some addictive behaviors, and has promising applications with others.”

Interestingly, patients addicted to nicotine, alcohol or drugs generally saw improvements associated with refocusing the mind or rebalancing the various physical and mental effects of stress.

According to science, sensory deprivation helps patients overcome addictions by:

  • Induction of a general relaxation response

  • Serenity and relief by non-chemical means

  • Internal refocusing to concentrate on personal problems

  • Disruption of habits through removal of trigger cues and response possibilities

  • Increased feelings of control over addictive behaviors

  • Enhanced learning processes

Research findings related to treating addictive behaviors with REST now support its use for:

  • Quitting smoking

  • Overeating

  • Alcohol consumption

  • Drug misuse

The most support for floating involves smoking cessation help, while many believe more research is needed overall to recommend floating for other drug problems.

How Does It Work?

What does sensory deprivation do? Sensory deprivation tanks help induce a deep state of relaxation (also called a “relaxation response” or RR) by turning down the body’s “fight or flight” stress response.

Evoking a natural relaxation response is considered an effective remedy for stress-related symptoms because it activates the parasympathetic nervous system, while at the same time decreasing activity of the sympathetic nervous system.

Essentially, floating helps lower cortisol levels and calm the nervous system, bringing the immune and hormonal systems back into balance.

Studies show that self deprivation sessions can help lower the heart rate, normalize blood pressure levels, restore a normal breathing rate (respiratory frequency) and normalize digestive functions.

In stressful or busy situations, we’re best able to induce a relaxation response by decreasing sensory input and bodily movements as much as possible. During a flotation therapy session, nearly all incoming stimuli and sensations are reduced or completely eliminated.

There is no music playing, no guided meditation or directions, and nothing else to hear besides your own breath. There are no lights — tanks are kept very dark.

Floaters don’t even feel water on the skin because it’s heated to nearly exact skin temperature.

Can you sleep in a sensory deprivation tank? While it’s possible, this is not the purpose.

Time in a sensory deprivation tank is similar to solo or guided meditation in that the mind tends to become very peaceful, allowing stress to melt away, but you remain awake. Who Should Try Floating?

Floating enthusiasts told the New York Times that anyone looking to “stretch thei