It can reduce stress.
“Reading can even relax your body by lowering your heart rate and easing the tension in your muscles. A 2009 study at the University of Sussex found that reading can reduce stress by up to 68%.”

It provides us with a healthy escape.
Reading takes us out of our world (and minds) and into another world inside the pages of a book. “With a film or TV show, you’re given the visuals whereas with a novel you’re inventing them yourself, so it’s actually much more of a powerful event, because you’re involved…”

It can make us more understanding.
Researchers at The New School in New York City have found evidence that literary fiction “improves a reader’s capacity to understand what others are thinking and feeling.” Another study “drew a strong connection between reading fiction and better performance on widely used empathy and social acumen tests.” We’re all better off when when understand what others are experiencing.

It gives us an opportunity to identify with others in similar circumstances.
When we read about others with similar experiences, we can feel less alone. This is especially good for youth facing challenges. “…there are now more and more young adult novels which can help teenagers by addressing head-on the issues they may be dealing with in their day-to-day lives, from bullying to drugs to transgender issues and social exclusion….”

More on the Subject
Literature as a Lens to Understand Trauma (NAMI)

“Reading for Stress Relief” (University of Minnesota)

“Can Reading Books Improve Your Mental Health?” (Psychology Today, May 2019)

“How Reading Fiction Increases Empathy and Encourages Understanding” (Discover)

“Can Reading Really Improve Your Mental Health” (BBC, May 2019)

“Reading Fiction Improves Brain Connectivity and Function” (Psychology Today, January 2014)

“Novel Finding: Reading Literary Fiction Improves Empathy” (Scientific American, October 2013)

Source: Why Reading is Good for Mental Health - NAMI California