Drugs’ effects on aggression are heterogeneous given the varying effects of each drug class (Pihl & Sutton, 2009). Acute and chronic cocaine misuse is a reliable correlate of aggressive behavior (Licata, Taylor, Berman, & Cranston, 1993; Murray et al., 2003). Other central nervous system stimulants (e.g., amphetamines) also increase aggressive acts by magnifying arousal and antisocial impulses (Dawe, Davis, Lapworth, & McKetin, 2009). Sedative (e.g., alprazolam, diazepam) and opioid (e.g., heroin) misuse are both positively correlated with a greater frequency and severity of violence perpetration, likely due to impairments in impulse control (Chermack et al., 2008). Conversely, marijuana intoxication is associated with reduced aggression in a dose-dependent manner (Myerscough & Taylor, 1985). Polydrug users (i.e., those who misuse more than one drug), reported higher levels of physical aggression than mono-users (those who only misuse a single drug) who in turn reported higher levels of aggression than non-users (Steele & Peralta, 2017). The evidence is clear that alcohol and drug misuse are both robust contributors to aggression and often overlap within aggressive individuals.
