Why is that only christians gets to be possessed by evil and other religions don’t?
Islam has the jinn and other supernatural entities.
Judaism has the dybbuk.
Even Buddhism has some believers in demonic possession.
Of course, voodoo also has demons and loa who can possess people, but that comes from the catholic part of its ancestry.
All religions believe their mental illnesses originate with their supernatural boogeyman.
The Catholic Church still does apart 200 exorcisms a year worldwide. Pretty barbaric and they could do more but they send out a team and in most cases refer the people to a shrink. (At least most of the ill people get real help)