Float therapy, also called restrictive environmental stimulation therapy (REST), is considered to be an alternative treatment in North America for physical and psychological problems.  Interestingly, it is accepted as a medical treatment in some European countries (13).

Float/REST involves lying in an isolation tank filled with body temperature water and 1000 pounds of Epsom salt. The environment is designed (8) to reduce or eliminate sensory signals like the following: auditory or sound; gravity; gustatory or taste; olfactory or smell; proprioceptive channels or movement/position of the body or it’s parts; speech; tactile or feeling; thermal or temperature; vestibular or inner ear re: give information about balance, motion, and overall equilibrium; and spatial orientation or the visual system.   If you choose to try float therapy please keep in mind that while some  report feeling the benefits of float/REST immediately, others take up to three sessions to experience them.

Float/REST has been proven beneficial in clinical studies for the following problems: stress, anxiety disorders (including generalized anxiety and social anxiety), burn out, depression, and pain management (including fibromyalgia, headache and arthritis), and sleep hygiene.  It is reported to improve a sense of wellbeing and optimism.  It is currently being studied as a treatment for PTSD (post traumatic stress disorder), autism, panic disorder, obsessive compulsive disorder (OCD), anxious depression, and mania in bipolar depression (anxiety, anger, and dysphoria), as well as the acute state of schizophrenia. It is used for addictions treatment.

Positive effects of Float/REST in clinical trials are as follows: improving sleep quality, optimism (1;9), and a sense of well being; increased breast milk production; lowered blood pressure (6);  and enhanced creativity, athletic and musical performance.   Regarding the time it takes for the maximum benefits to be felt, in clinical trials Float/REST has shown that after 12 (45 minute) sessions (two per week), the individual will get the maximum desired pain and stress relieve (13).

Float/REST  reduces stress hormone cortisol, which is associated with depression, anxiety, and burn out. By simply reducing cortisol production the production of feel good neurotransmitters serotonin and dopamine is increased.  This therapy also lowers production of anxiety related  fight or flight response hormones like adrenaline.

To learn more read on.

Psychological impact: Float therapy has been shown to reduce negative psychological qualities or experiences while increasing positive ones, improving immune function, and lessening perceptions of pain (1; 2). Regarding stress, floating is more effective in those suffering from severe stress (harder to get to respond to stress reduction) than other techniques (13).

An example of this is the following study result: after 12 float sessions participants  (male and female) reported experienceing less pain, anxiety, depression, and stress.  Conversely, the subjects’ sleep quality and  feelings of optimism improved.   The nursing mothers’ taking part in the study found their breast milk production improved. The last was as breast milk related hormone prolactin increased.    This should not be overlooked as this hormone is also essential to all humans regarding metabolism, pancreatic development, and regulating the immune system.   It also helps males make sperm, and it plays a part in maintaining the myelin coating, or sheath of fat, that coats axons in the central nervous system. This facilitates communication in parts of the nervous system ( it is whatdegrades if an individual has multiple sclerosis or MS ).  All of these benefits, other than the prolactin, were maintained for up to 4 months after the last float session (2). In other studies subjects  have reported feelings of euphoria, increased creativity, and altered states of consciousness (13).

Burn out: for those individuals who are experiencing burn out and a lack of desire to continue working, or for those on leave, to return to work,  float therapy may be benefitial. In a small (six participant) study on the  effects of combining float and talk therapy for 10-weeks,  all of the participants reported both an ability to continue working full time (including going back to work), and improvements to their quality of life, and positive psychological transformations or experiences (7).

Generalized anxiety disorder: is being explored regarding float therapy, which shows promise as a treatment for generalized anxiety disorder. For instance, in a human trial 37% of the treatment group had reached full remission, and problems with emotional regulation (controlling emotions), sleep, and depression, had improved. The improvement to all these benefits, accept depression, were sustained for six months (3). This may be as float therapy has been shown to reduce levels of the stress hormone cortisol, along with levels of adrenocorticotropic hormone (ACTH), the hormone that regulates the adrenal glands (4).  It should be noted that cortisol production disrupts the production of feel good nerotransmission serotonin.  Further, if cortisol is completely depleted (a condition medically called adrenal fatigue), the body has  more trouble  metabolizing glucose (sugar) so energy decreases. This leads to disrupt brain function, fatigue, and yet more problems maintaining neurotransmitter balance.  This condition inevitably leads to more depression, more anxiety, and more stress.

Float therapy reduces activity in the area of the brain most associated with the stress response, the pituitary-adrenal axis. Here ACTH (which increases cortisol) is released in reaction to stress. ACTH is related to circadian rhythms, and so, to sleep. it is produced when the HPA axis (hypothalamic-pituitary-adrenal axis) is stimulated by a potential stressor. Long term activation results in, or contributes too, many health problems including anorexia, cardiovascular disease, depression, diabetes, hypertension, obesity, and osteoporosis (17).

Why float/REST may work for psychological problems: lies in its impact on stress related hormones, which are decreased by floating. The HPA (hypothalamic-pituitary-adrenal) axis plays a primary role in the stress (fight or flight) response. Its hormones (ACTH, epinephrine, nor-epinephrine, cortisol, and aldosterone) have been shown to lower during float therapy. This effect can last up to four months (16). The HPA axis (17) both affects, and is affected by, different brain and nervous system components. The HPA axis can also alter its functioning in response to environmental influences. The HPA axis hormones can influence the autonomic nervous system, which controls these vital bodily functions: body temperature, pain, appetite, blood pressure, heart rate, and digestion. It also works with, and is affected by, many areas of the brain. These include the limbic system (brain region known to control mood and motivation), the amygdala (fear, responses to danger), and the hippocampus (memory formation, motivation and mood).

Other psychological problems Float/REST therapy has  positively impacted in clinical trials include: PTSD (post traumatic stress disorder), panic disorder, depression, anxious-depression, and mania in bipolar depression (anxiety, anger, and dysphoria), and the acute state of schizophrenia, as well as addictions.  It is showing promise in case studies as a treatment for possessive compulsive disorder.

In one study, after three weeks of float therapy, subjects had lower circulating levels of the fight or flight response related hormone/neurotransmitter noradrenaline metabolite 3-methoxy-4-hydroxyphenyl ethylene glycol (MHPG). It was reduced significantly in the float group, but not in the control group (10). This metabolite plays a principle role in the degradation of norepinephrine (also called noradrenaline in the brain and adrenaline in the blood). The presence of MHPG in blood samples suggests that there has been recent sympathetic nervous system activity. It is higher in people under stress, or in those experiencing emotional distress. Here the peripheral nervous system is over-active,  leading to: anxiety, emotional instability, insomnia, irritability, and (exaggerated) fear and aggression. These are symptoms of post traumatic stress disorder, panic disorder, generalized anxiety disorder, anxious depression, and mania (anxiety, anger, and dysphoria) in both bipolar depression, and schizophrenia (acute state), amongst others. This might explain the reports of individual war veterans who state that Float therapy helped treat/ameliorate their PTSD symptoms, even when other therapies failed (28;5).

Over production of norepinephrine/noradrenaline can lead to a depletion  of it in the neurons that respond to it. This may happen either through a degeneration of the neurons themselves, or by a slowing of production of noradrenaline. This depletion leads to an under-active nervous system and symptoms of depression, including the following: hypo-arousal symptoms like insensitivity to stress, and increased tiredness or excessive time sleeping, called hypersomnia (10), as well as a lack of motivation, impaired cognitive processes (including intellectual skills), and poor appetite. A depletion of norepinephrine is also associated with the eating disorder anorexia, and with gambling addiction.

Currently research is being done (using fMRI technology and waterproof electrodes) to see how float therapy is affecting the amygdala, where humans process fear and rage.  This is the area of the brain affected by the Anti-anxiety drug Ativan, (Lorazepam a benzodiazepine).  It is the amygdala that first gets information from the eyes and ears (sense organs) about potential danger. The amygdala decides whether the sights and sounds signal danger. If they do, a distress signal is sent to the hypothalamus. This is the area of the brain that communicates with the body regarding the stress response, called fight or flight. The hypothalamus uses the autonomic nervous system to do so. This system controls the following: breathing, blood pressure, blood vessel dilation/constriction, and heartbeat. It is broken into two parts, the sympathetic nervous system and the parasympathetic nervous system. The first revs the body up for a fight or to take flight, the second calms it down after the danger is over (29).

During fight or flight the hypothalamus first signals the adrenal glands to release the hormone adrenaline (or epinephrine), this fuels an initial burst of energy.  As the adrenaline rush dissipates, the hypothalamus initiates the second part of the stress response by producing stress hormones in the HPA axis. This system is responding to the hypothalamus releasing CRH (corticotropin releasing hormone). This substance goes to the pituitary gland (in brain) which in turn makes ACTH (adrenocorticotropic hormone). ACTH then goes to the adrenal glands, which produce cortisol. This system keeps the body in the stress (fight/flight) response. When the brain perceives the stressor as having passed it should activate the second system, the parasympathetic nervous system.  This is known as the rest and digest system. When it is activated the following happens: sweating decreases, digestion increases, heart rate lowers, pupils constrict, blood pressure lowers and the heart rate slows and the heart muscle starts to relax.  But, if someone is under stress for a long time, this fails to happen, and the body is always producing low levels of cortisol. This situation leads to chronic stress and anxiety, and concurrent health problems (29). These problems include cardio vascular problems and obesity/weight gain. The first is as constant upswings in epinephrine damages arteries and blood vessels, causes high blood pressure, and increases the risk of stroke or heart attach. The second is due to increased appetite and higher amounts of unused fat being stored in the body (29).  Increased cravings for sugar, and simple carbohydrates, are the body’s way of directly providing fuel ( in the form of blood sugars ) for the flight or fight response. This lowers, or turns off,  the production of cortisol.   Cravings for high fat foods, and the storage of excess fat, are meant to provide  The building blocks to make cortisol.

It is the amygdala which is usually affected by the anti-anxiety drug Ativan (Lorazepam, a benzodiazepine). Regarding the fMRI study, the results are reported as looking promising. The primary researcher, Dr. Justin Feinstein, has stated that “the preliminary data is that the amygdala is shutting off post-float. (5).”  These findings confirm other studies on the effects of float therapy, the benifits of which, after 12 sessions, have been shown to last up to four months (2).

Dr. Feinstein recently gave one float session each to 50 participants to see if one session alone could be beneficial. The participants reported a range of psychological problems: agoraphobia, anxiety (including generalized anxiety and social anxiety), depression, post traumatic stress disorder, and panic disorder (8). Each person was given the Spielberger State Anxiety Inventory before and after the float session. It was found that one float session alone resulted in a robust decrease in felt anxiety, and a significant enhancement in mood (happiness, overall well-being, relaxation, and serenity). These results were Reported by the entire group (8). Furthermore, Float/REST greatly reduced reported depression, muscle tension, pain, negative affect or emotionality, and stress. The anxious test subjects, in comparison to low/no anxiety subjects, experienced a greater response to floating. In fact, many tested as approaching non-anxious levels post-float. More important still is the fact that those with the highest reported anxiety to start with had the greatest reduction in distress.

Float therapy holds promise as a treatment for attention deficit hyperactivity disorder (ADHD), and Asperger syndrome, as well as being used in conjunction with psychotherapy for addictions (13).

Learning, creativity, and performance: floating can increase creativity and originality, while altering states of consciousness. This may be as sensory deprivation reduces what is called secondary processes, thoughts about current life events and abstract thinking (logical,  abstract, analytical, reality oriented), while increasing primary processes like imagination, intuition, and focus on the present (13).

A study using the Guilford Creativity Scale, the State Personality Inventory (SPI), and the Profile of Mood STATES (POMS), found that the subjects who took a 1 hr float were more creative, and had greater vigor, while also having  lower scores on anxiety, depression, fatigue, and tension (23). Those individuals who tested as more creative before floating showed a greater reduction in measures of depression and hostility compared to  lower creative types, and those in the control group (sat in relaxing environment). Specifically, women who tested as very creative to begin with decreased their fatigue and depression scores; and pre-test highly creative males lowered their scores on hostility. These subjects also showed a greater response to floating re: lowering anxiety, confusion, fatigue, and tension (23).

A small study on university professors found that subjects were more creative regarding generating research ideas post float vs. sitting in their offices relaxing. Further, mood ratings indicated that REST/float was associated with greater levels of vigour, and lower levels of anger, depression, confusion, fatigue, and tension (24).

Another study, on university students studying intermediate level jazz improvisation, found that the students who floated 1 hr per week had higher ratings in improvised pieces, technical ability, and higher final grades (25).

Athletic performance: has been improved by floating. Here the unwanted effects associated with stress were reduced, and restoration after competition and training were accelerated (13). Floating has been shown to lower blood pressure and help dilate arteries for greater blood flow (13). This would assist in injury healing. Floating has improved perceptual motor skills in sports (25). For instance, in a test on archers, those who floated for 45 minutes prior to marksmanship training had less perceived exertion during the training, had more consistency regarding their performance, and showed lower muscle tension (27).

Float/REST induces a more obvious primary process condition, or deeper concentration. This state positively influences the closed skills needed for self-paced sports (archery, diving, ice-skating, and marksmanship). This skillset includes the following: immediacy-focus, cognitive shift from verbal based (left) hemisphere to spatially dominated (right) hemisphere, narrowed span of attention, and relaxation (27). This skill set can be used, if combined with visualization exercises in the tank, by coaches and athletes to reinforce (primary processing) desired skills/outcomes (27).

The reason for these changes may be that float/REST may elicit cerebral (brain) changes similar to those proposed in the Dynamic Hemispheric Asymmetry (DHA) model. This suggests that float/REST allows the normally non-dominant part of the brain (cortical hemisphere) to become more active, and have greater influence on both affective (emotional) and cognitive (thought) processes. This model hypothesizes that float/REST engenders more cortical hemisphere control, resulting in the positive results of studies on float/REST subjects. These individuals were found to be more perceptive and creative, while experiencing more brain activity (learning, memory, imagery, divergent thinking), as well as being more flexible regarding habits and attitudes (26).

Immune response: float therapy increases production of the hormone prolactin. This hormone, best known in association with breast milk production, is essential in metabolism, pancreatic development, and regulating the immune system (13). One study found an enhanced immune response after floating, with an increase in T-lymphocytes and B-Lymphocytes (13).  Lymphocytes are white blood cells and they take part in the immune system.   These cells identify non-self antigens (invaders) and they generate specific responses tailored to eliminate these specific pathogens or the pathogen infected cells. B cells attack bacteria or viruses by producing large quantities of neutralizing antibodies. T cells  produce cytokines that directly immune response or produce toxic granules contain powerful enzymes that kill pathogen infected cells.  Prolactin helps men make sperm (14) and, in both sexes, plays a part in maintaining the myelin coating, the fat that coats axons in the CNS (15). This is important regarding brain health.

Regarding pain management and healing: float/REST therapy is shown in clinical trials to significantly benefit the following pain related features: decreased pain in general, decreased muscle tension, decreased pain caused by muscle tension, lessening of anxiety, magnesium absorption, mood elevation, and stress reduction (11). In fact, stress related pain is significantly reduced by float therapy (2). After 12 sessions, 70 human subjects were able to sustain the positive effects for up to four months. Regarding pain management specifically this study: concluded that floatation tank therapy is an effective method for the treatment of stress related pain” (pg. 154, 2).

Chronic Muscle pain (neck/back area) was shown in a clinical trial to improve, in both sexes by float therapy (9). Here 20 people were given nine floats over a three-week period. Most reported a significant improvement in sever perceived pain intensity.

Fibromyalgia sufferers response to float therapy has been studied. in this condition stress may both cause and trigger the symptoms of Fibromyalgia (effecting 2% of the population, with more women effected). Fibromyalgia symptoms include widespread pain in both muscles and bone (musculoskeletal pain), which is described as a dull ache arising from muscles. These can be constant and include knots that are trigger points, tension headaches and temporo-mandibular joint pain or TMJ. Other symptoms include irritable bowel syndrome or IBS, an inability to sleep restfully, and mood disturbances (anxiety and depression).

Fibromyalgia is benefitted by as little as three float/REST sessions (11). Participants experienced the following reductions: in pain, how much they were bothered by pain, muscle tension, anxiety, stress, and sadness. They also experienced an increase in the following: ease of motion, well being, relaxation, and increased energy. Importantly, the improvement was found to be cumulative over the sessions leading to longer term effects (11).

Other conditions positively impacted by floating include rheumatoid arthritis, muscle tension, headaches, and back injury (11). Headache sufferers may find release as migraine headaches may result from magnesium deficiency as it relates to neurotransmitter release and vasoconstriction. Individuals who suffer from this condition have lower levels of magnesium in the blood (12). The American Academy of Neurology and the American Headache Society together concluded that magnesium therapy is prebaby effective in the prevention of migraines (12). See a health care provider before pursuing this line of treatment. Floating may positively impact bone health and vitamin D absorption. Magnesium affects bone health as it influences the concentrations of both parathyroid hormone (so it helps thyroid problems) and the active form of vitamin D. these are both needed for bone homeostasis. So, magnesium is needed to maintain bone mineral density in both sexes (12). Women with lower levels of magnesium are at greater risk for osteoporosis.

Why float therapy works on pain: is due in part to the increase in magnesium. Magnesium deficiency is associated with numbness, tingling, muscle spasms, cramping and twitching, personality changes, seizures, abnormal heart rhythm, and coronary spasms (12). Interestingly bowl problems, (IBS is a symptoms of fibromyalgia) is known to cause magnesium deficiency.

Epsom salt (magnesium sulphate heptahydrate) may be absorbed through the skin and into the blood. There is some experimental evidence to support this (18). Magnesium has been shown in studies to be absorbed through hair follicles and sweat glands, which make up 1% of the skins surface. This doesn’t sound like much but given that the skin makes up about 10% of body mass and is the largest organ in the body, so it can still have an effect. Samples of blood, urine, and hair indicating magnesium levels post transdermal (skin) absorption were higher after exposure to Epsom salts and remained higher for 24 hrs (18).

The sulfur in Epsom salt baths, proven to penetrate skin (21) is theorized to help increase an enzyme in cells called phenol sulfotransferase (PST). This happens in the body after the sulfur from bath water, with the help of bodily processes, is changed to a sulfur the cells can use. PST attaches the sulfate to other molecules (phenols) which are then more likely to be excreted in urine, leading to detoxication (22). This is very important as if your body lacks sulfur, phenols accumulate and can interfere with CNS functioning. So, phenols negatively effect many neurotransmitters (22). An example is catecholamine sulfotransferase or M-PST, a type of PST that acts on neurotransmitters.

Other forms of sulfotransferase impact not only neurotransmitters, but hormones, proteins, and carbohydrates. All of these components impact cellular health (22). Besides PST, sulfur helps make molecules governing the cell surface regarding chemical traffic (extracellular matrix) and is necessary for proper cell signalling by ions. This is true of cells in the areas of the brain that process information about the senses, called the auditory, somatosensory, and vestibular (balance, motion, spatial orientation) systems, and the cerebellum (regulator of sensory systems regarding voluntary motor movements like speech, posture, coordination, muscle activity) as well as many cranial nerves (nerves going from brain to sense organs).

Besides the above, Float/REST may have success with pain as it has other effects on neurotransmitters. For instance, those suffering form fibromyalgia have abnormal increases in pain signalling neurotransmitters. Perhaps because pain receptors in the brain appear to develop a memory of pain and become sensitized to it, leading to overactions to pain signals (11). Those suffering from fibromyalgia have increased pain sensitivity, meaning that the connection between pain and arousal is amplified. So, an increased pain sensitivity leads to higher arousal and exaggerated perception of pain (11).

Float sessions may, over the long term, reset the central pain sensitivity. Self regulation is the result of float/REST sessions as it focuses attention away from external events and onto internal (mental and physical) events. Here the individual is repeatedly exposed to physical symptoms while in a deeply relaxing (calming mentally and physically) environment. The brains sensitivity to pain may be reset by this combination of pain sensation and low arousal levels. This effect is likened to the reconditioning of the emotional context of a traumatic memory during a deeply relaxed state (11) perhaps like EMDR therapy.

Skin appearance and health: is improved by bathing in Epsom salts. Water rich in magnesium has been shown to improve skin because it binds to water, influences skin health (20). Magnesium improves moister content and the way it regenerates and changes (proliferation and differentiation).

A study on dead sea water and dry skin found that submerging limbs for 15-minute intervals in magnesium rich water Repeatedly for six weeks resulted in improvements to the following: trans-epidermal water loss, skin hydration, skin roughness, and skin redness/inflammation. The researchers said that bathing in magnesium rich water “significantly improved skin barrier function compared with the tap water treated control” (pg. 1, 30). In other words, magnesium baths moisturize (hydrate) skin. Those with the greatest problem with trans-dermal water loss experienced the most improvement (20).

Regarding weight loss: magnesium supplements have been shown to reduce body fat in women (19) and this may be why some people have claimed to experienced weight loss/reduction in inches after floating.

This information is for educational and informational purposes only.  It is not to take the place of medical advice or treatment.   Seek out a qualified health care provider if you have questions or need help.  Dr. Grant is not responsible for any possible health consequences of anyone who follows or reads the information in this content.  Everyone, but especially those taking medication (over the counter or prescription) should talk with a physician before undertaking any changes to their lifestyle or diet (including taking supplements).

This information has been copy written.

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