What is Masturbation?
Masturbation is stimulating one own genital for sexual
pleasure.

Masturbation is a serious psychological and sexual
urge that is very hard stop once one start practicing it. Is
like alcohol once you are addicted, stoping it is very difficult. What leads one to Masturbate is very
versatile but their is one thing which is the root of it. Yes
you get it right! only one thing can lead to Masturbation,
and what could that be if not almighty pornography!


Pornography is the chief cause of Masturbation :
Many people who made to quit this habit told me many
times that only if they avoided pornography early
before, there is no way one will be addicted to it.
So from what I got from people in real life I can
confidently conclude that pornography is major cause of
Masturbation. Their is other cases that leads to it, but
pornography is the pilot teleporting them to become
easily and unimagine things that arose the urge to
masturbate, now you know the cause of Masturbation,
let look at the possibly ways of getting rid of it.

Avoid pornography!

This is only way you escape this trap called
Masturbation. When I said avoid pornography it is not
only about porn videos and pictures, but you also have to
delete all those pornography you have created in mind
and stop thinking about it. Deleting them requires to
come up with something that will keep you busy any
time your mind goes there. Doing this repeatedly will
gradually eliminate those pictures and feeling-like, you
always have before Masturbating

Source: https://www.uchehub.com.ng/2018/02/the-only-way-to-stop-masturbation.html?m=1

So if they can't view new ones can't they imagine the old ones and do their thing? Since you said its psychological.