Is there a psychological cause to rage flare ups?

Could be: I'd suggest seeing a psychiatrist to try to diagnose the problem and recommend treatment.

Very possible: It's very possible for rage flare ups to have a psychological cause. Humans are complex beings, and have complex responses to things. Even if a person is under the influence of drugs or alcohol, s/he will process things according to his or her unique psychological make-up. In fact the more out of reality contact the person is, the more s/he will respond according to inner than outer stimuli.