I don’t. It’s actually kinda one of my pet peeves: people misunderstanding psychopathy or sociopathy and throwing around the term casually, without realizing that the term is outdated and is a way of spreading fear about a very real and very sad personality disorder. The medical term is antisocial personality disorder, and it’s a very complicated diagnosis to make that requires a degree on behalf of the diagnoser and interaction and observation of behaviors, all of which are impossible to make in relation to a fictional character.
It’s different to talk about how characters are coded a certain way–for example, in Tokyo Ghoul Kaneki is clearly coded as suffering depression, and Mutsuki with a dissociative illness, and in Star Wars Kylo Ren is coded as mentally ill–but you can’t actually diagnose a character like Kenny or any of them, especially with complicated illnesses like personality disorders. I do think Kenny displays traits of such a disorder, but I wouldn’t say he’s got antisocial personality disorder.
I also get uncomfortable because usually such fictional diagnoses are then used to condemn the character, and to condemn fans for feeling empathy for such characters, which is really quite ablest. To be diagnosed with a mental illness a patient must undergo evaluations by trained experts, and personality disorders like Antisocial Personality Disorder, are extremely complex and really need careful evaluation.