It's true. It's one of those justifications that you will hear crafters use, but they aren't pulling that out of thin air. According to Psychology Today, knitting can be greatly beneficial for those with eating disorders, trauma, and obsessive disorders. They claim it can be a productive way to distract oneself from bad habits like smoking or binge eating and can even fight against dementia.
Some say that in today's world, people like to keep their hands busy. Knitting keeps your hands busy but keeps your mind free. This way you can still interact with others and avoid staring at a screen.
Research shows that moving your eyes from side to side is a good therapy technique. It's used with trauma victims and it's also used in certain yoga practices. Luckily, it's something that happens naturally while knitting.
Chronically ill and differently abled people often report a feeling of aimlessness. Reports show a decrease in these feelings in those who pick up knitting. It can provide a sense of purpose and a sense of accomplishment.
I don't know about y'all, but I also enjoy the gratification of making an item by hand, be it for me or a gift. Knitting also gives me something to look forward to every day. It's a common theme of my day-dreams, when I'm thinking of what to knit next. Knitting has also brought many wonderful friendships into my life and fun day trips and memories I will never give up.
In summation, pet the yarn, pick the project, knit and crochet to your hearts content. It's what the doctor orders!