The Cleveland Clinic released an article on the benefits of adult coloring last year—
What does adult coloring do to relax people?
Dr. Bea, clinical psychologist, cites three reasons adult coloring can be calming:
1) Attention flows away from ourselves. A simple act, such as coloring, takes your attention away from yourself (and those things that are stressing you out!) and onto the present-moment event. “In this way, it is very much like a meditative exercise,” Dr. Bea says.
2) It relaxes the brain. When thoughts are focused on this simple activity, your brain tends to relax. “You’re not disturbed by your own thoughts and appraisals,” he says. “The difficulties of life evaporate from your awareness, and both your body and your brain may find this rewarding.”
3) Low stakes make it pleasurable. Go ahead: color outside the lines! The outcome of coloring isn’t predictable or prescriptive. It can be as neat — or as messy — as you choose, and this is one of its relaxing perks. “It is hard to screw up coloring, and, even if you do, there is no real consequence. Adult coloring can be a wonderful escape, rather than a demanding test of our capacities,” he adds.