Of what little I know, anxiety is a symptom of the disease especially paired with delusions of various kinds. The side effects of most anti-anxiety meds actually worsens the symptoms even if there is a temporary placebo effect when the meds are first prescribed.
He almost always feels better if he has anxiety, getting some rest or doing a relaxation exercise that doesn’t require medication is what we usually recommend for him. (Although he insists at that point that he doesn’t need his meds when he can lessen his anxiety with exercises, why can’t he handle his delusions without it too?) This doesn’t fly and in as much as we can make him realize something, he knows most of his things that he likes, like having people visit are contingent on him being able to take care of himself.