One of the main ways in which psychotherapy helps people is to enable them to experience difficult and/or unconscious emotions in a safe environment where they are not judged as good or bad, but seen as an authentic expression of part of the self than can and should be understood. The corollary of this approach is that emotions only become bad when they are suppressed. A new study published in the journal Addiction seems to corroborate this view by demonstrating that that drunkenness increases the risk for violent behaviour, but only for individuals with a strong inclination to suppress anger.

http://www.sciencedaily.com/releases/2010/06/100621121356.htm