Taken together, this evidence suggests that the association
between substance use disorder and aggressive
behavior in schizophrenia is complex. It could be partly
direct causative effect that depends on the acute pharmacological
activity of the substances and the associated
criminogenic factors, partly an epiphenomenon that is
independent of the pharmacological effects: It is the
antisocial personality/psychopathy that causes aggression,
while covarying with substance use disorder.
Statistical analyses that do not account for personality
disorder then show a strong association of substance
use disorder on aggression, but a major part of that association
is not causative