Someone in the mental health profession told me the difference is that if you have Paranoid Personality Disorder--medications don't help that much, rather, committing to intensive therapy for a long time is how you treat it. She also mentioned that if you have PPD, you could jump to delusions quickly and easily. Another person, a psychiatrist, told me that with schizophrenia, you don't have to hear voices or see things that aren't there, rather, it could be a significant change in effect (I think she meant severe changes in how they act and present--I find this article interesting: Emotion in Schizophrenia: Where Feeling Meets Thinking) I would surmise that that comment means that medications are an important part in the treatment of Paranoid Schizophrenia (though therapy is probably needed too but the emphasis might be different?) Have you asked a psychiatrist or psychologist?