If you mean to call extreme arousal psychologically causing PE, I'd say I think they're completely different things. What I mean is, I wouldn't call extreme arousal, a psychological issue.
When you're aroused your body changes. You heart beats faster, your skin flushes, you become erect, drugs are released, your body prepares for stimulation and copulation. Your arousal also affects your stimulation. A flaccid, non aroused penis when stimulated does not feel the same as if you had your erect penis stimulated while in a highly aroused state. I wouldn't call that psychological.
However, you might say your psychological mindset determines why one man becomes overly excited and another only becomes mildly excited. That I don't know. How much is nature (your dna, biology, chemicals in your body, etc.) and how much is caused by your thought and experiences.
Either way it sounds like your arousal level plays a large role in your ability to orgasm. And it sounds like your refractory period affects the level of arousal you reach and therefore the difficulty in reaching another orgasm.
PE is psychological in many ways. If you're stressed or feeling sexually inadequate it may play a role. Even if it is just to make you tense and unable to relax the muscles that trigger ejaculation. The book, Coping With Premature Ejaculation breaks down many causes, and if you're in a relationship it may be especially helpful.