This is totally true. I've had a Chrisitan priest tell me masturbation is totally harmful to young men. He told me it destroyed their nerves, made them fearful, less intelligent and it brings many illnesses.
I took this to heart as I was a young boy at the age of 18 and fell into depression and anxiety many months later.
These types of advices can totally destroy young teens.
I had a similiar thing done to me except I was told I was going to hell for masturbating and that even thinking about having sex was evil. Totally screwed me up when it comes to sex.
When you feel vulnerable and your psychological defenses are failing the best defense mechanism is to be more trusting.