Studies have found (surprise surprise ) that some methamphetamine users engage in violent behavior because of the physiological effects of the drug. Drug-induced psychosis occurs more commonly with methamphetamine abusers, than among abusers of other stimulants such as cocaine, probably because methamphetamine has a longer lasting affect on the user, than other stimulants do.
For example, smoking methamphetamine produces a high that lasts 8–24 hours, compared with 20–30 minutes for smoking cocaine. Although psychosis does not necessarily lead to acts of violence, some clinical studies have supported the hypothesis that methamphetamine increases the likelihood of violent behaviors and aggression in humans, leading to the concern that public safety may be threatened by high level methamphetamine users, whose anxiety, and paranoia may prompt a violent reaction when they are in contact with other people, especially if in a confrontational situation ie: in the company of police or medical professionals.
In another study of methamphetamine users admitted to treatment in Los Angeles, nearly two thirds of the participants cited violent behavior as an outcome of their usage. It was found that nearly half of methamphetamine using subjects reported being involved in violent crime, and 24% reported that their involvement in violent crime was a direct result of their methamphetamine use. Another study, specific to methamphetamine use in five western cities, found that one third of methamphetamine-using arrestees cited violent behavior as a consequence of their use. Also, methamphetamine-using arrestees were more likely to have been arrested, and incarcerated previously than their non-methamphetamine-using peers.
Methamphetamine users attributing blame on methamphetamine for the causes of their behaviors may not be entirely accurate. However, a study conducted in 2004 suggests a relationship between chronic methamphetamine use and violence. The investigators compared certain fighting behaviors (number of initiated bite attacks and latency before attacks) between mice that had received a single injection of methamphetamine (6 mg/kg) versus chronic injections (over 8 weeks). The authors found that the single injection did not increase fighting, but chronic injections were associated with increased attacks and decreased latencies.
von Mayrhauser et al., 2002
Wright and Klee 2001
Pennell et al., 1999
Dillon et al., 2000
Sokolov et al. (2004)
...to be continued