The consumption of psychoactive substances has long been considered a significant factor predisposing to violent behavior. This is especially taken for granted regarding individuals with addictions to them. However, it is also indisputably true that the presence of dysfunction in the violence inhibition mechanism and psychopathic predispositions serves as a precursor to such behavior. Therefore, researchers became interested in the extent to which psychopathic traits influence the link between psychoactive substance use and violence.
In the past, some studies were conducted regarding the link between alcohol consumption and aggressiveness in animals and humans. Many of these studies concluded that alcoholism itself cannot be a factor predicting violence. In experiments on mice, aggressiveness from alcohol consumption increased only in individuals with significantly reduced levels of serotonin receptor mRNA in the brain (and, as is known, the serotonin system is responsible for the function of the violence inhibitor). And in violent behavior resulting from alcohol consumption in humans, the level of psychopathic traits they possess plays an important role.
Current studies, conducted on criminals, reach similar conclusions when studying the influence of addiction to alcohol, cannabis, and cocaine on the propensity to commit violent crimes. Elevated psychopathy scores explain a significant portion of this influence, and if their mediating effect is taken into account, such a link becomes weak.
We can indeed observe more frequent acts of violence by people taking psychoactive substances. However, it seems that they are not the primary cause of such behavior and do not make a person more violent in and of themselves, but may only act as a provoking factor in the case of those individuals who are already prone to committing violence but simply exercised better self-restraint before consumption. Therefore, any intervention aimed at reducing violence from substance-dependent individuals must focus not only on the therapy of the addiction itself, but also on the therapy of the dysfunction of the violence inhibition mechanism, as it is this that remains the root of the problem.
