Important topic! It's similar to the issue of the psychological effect of violent books, movies, TV, and video games. Could reading a book with a violent plot, watching TV or movie violence, or playing violent video games make someone a worse person? I think maybe it could, at least in some cases. Also, I think the effect would depend a lot on the type of violence. If a movie, for example, glorifies senseless violence against innocent people, that's very different from a movie in which good people resort to violence to defend themselves or others from people who are trying to harm them.
An LD is very similar to being immersed in the plot of a book, watching a TV show or movie, or playing a video game, because you're experiencing something that you know isn't real. But even if it's not real, it could still have psychological effects. An LD might even have a greater effect than a book, movie, TV show, or video game. Because during an LD the subconscious part of the mind is more active than the rational part. So the mind may be more open to being influenced, in either good or bad ways.