My cat could not be held or petted without trying to bite. She would get so wound up, she would relieve stress by running laps back and forth down the hall from BR to den. I felt so bad for her. Would play the 'fishing' game for hours each day just to help her release up all that pent up stress and energy.
After moving to a new city, I took her to a new vet for her shot updates... a practice exclusively dedicated to cats. As soon as i walked in my cat was calm, let us pet her, let the vet look at her teeth - and all without a hint of aggression. That's when I noticed they had therapet in every outlet. Wow. I came home and immediately ordered 8 atomizers for my living/dining room, kitchen and BR. Have multiples in the larger rooms. Bless her heart, she is finally close to being a normal cat. Still does not like to be held very long, but at least she doesn't try to bite me when I happen to pet her. Worth every nickel just to see her finally able to relax.