Acute alcohol use is associated with suicide

[Earth Wind and Fire]

Lower serotonin activity is tied to increased aggression/impulsivity, which in turn may enhance the probability of suicidal behavior.

So is this correct. Chemical imbalances in the brain cause both aggressive & impulsive behavior? And is this common to alcoholics?

http://qjmed.oxfordjournals.org/content/99/1/57.full