The themes of adult coloring books are usually intricate and centered more around adult images, not your childhood counterparts that included bunnies, super heroes, and farm animals. You would expect to see geometric patterns, psychedelic patterns reminiscent of doodle art type pages, fantasy images including angels, dragons, goddesses and mermaids, and ancient designs of religious and spiritual nature.
So why the fascination, and how can they help you? In the most basic sense, the act of applying colored media to intricate line drawings is a benefit to relaxation and stress reduction. You are able to put the outside world aside for the moment and focus on the art of coloring singularly. Studies have shows that anxiety levels dropped in adults that colored. They did note that simple doodling had no affect on anxiety. The focus on coloring and switching off the brain allows that blocking of anxiety in the moment. Coloring does not have a need for complicated thought processes and like listening to calming music, you are able to get within yourself, isolated from external anxiety, commotion, and distractions.