Proven relaxation routines such as yoga, meditation, nature walks and listening to music aren't the only alternatives. A method known as flotation therapy, around since the 1950s, gains wider attention as a natural way to support mental and physical health. It involves bobbing in a dark, silent "sensory deprivation tank." That's a shallow pool or pod, kind of like a hot tub, with ultra-salty water that helps people float more easily. One goal is to retrain a user's focus by escaping distractions – particularly the constant deluge of information via digital devices. "Think about what a strange world our brains find themselves in, suddenly inundated with 24/7 connectivity," says Professor Justin Feinstein, an Oklahoma researcher who directs a float clinic at the University of Tulsa.

Users include pro basketball player Stephen Curry of the Golden State Warriors. "It's the only place that I've found in this world that you can eliminate all the senses, basically," he says. It helps with mental sharpness and "to try to master your thoughts," adds the NBA star. In a recent CBS News segment, morning co-anchor John Dickerson went to Feinstein's clinic in Tulsa to float in less than a foot of body-temperature saltwater for an hour. He felt weightless, unsure where his limbs end and the water starts. The sensation creates a clear, drifting mind – a bit like nearly napping.

Floating in the dark "powers down" the body, in effect. Dickerson's heart rate dropped by 20 beats per minute and his blood pressure fell more than 20 points, sensors showed. "I could go for that every day," he says. "I wandered out into the light energized and yet feeling empty from an hour of no conscious thought." Another first-timer, Harriet Allner of London, recently posted her impressions: "Time loosened. My mind became slippery – ideas skittered away almost as fast as they crossed my consciousness. My body couldn't hold tension either. My heart set a steady mantra, slow and familiar, my arms floated above my head, unraveling my spine. My muscles twitched, loosened, fell apart. At one point I was convinced my limbs had spun away, that my arms had been unstitched from my shoulders, my feet from my ankles, my legs from my hips. I had no sense of where my body began or ended – or what threads held me together."

User says: "To have that nothingness and be forced to just decompress -- there's something revitalizing about it. It keeps me more focused." – Scott McKenzie, business owner in Newport Beach, Calif.

Researcher says: "Here in many ways you have the ultimate form of disconnection. I don't know if this is going to be the solution, ultimately, to all of the problems that technology may end up causing our nervous system. But it seems like a very simple way to at least give a respite." – Justin Feinstein, University of Tulsa (Okla.)

Psychiatrist says: "Some people might find that very restful. Some people might find that it freaks them out." -- Dr. Philip Muskin of Columbia University