There are examples at dictionary.com on uses of 'schadenfreude'.
But what is the correct way to describe a person that has/uses/suffers from schadenfreude as part of a personality disorder/mental illness?
She suffers from schadenfreude? She's diagnosed with schadenfreude? She delights in schadenfreude? (probably not as the word itself tells us of the delight) She engages in schadenfreude? She commits schadenfreude?
I've no idea how to describe someone's mental illness where the primary symptom of this illness is schadenfreude.
What is the correct way to say this?
I see from the comments/answer that the question is wrong - I've asked correctly with more details here: Term for ASPD Specific for Causing Pain to Others