The American Psychiatric Association lists harmful mental effects caused by marijuana, including psychotic disorder, hallucinations, anxiety disorder, impaired judgement, sensation of slowed time, social withdrawal, perceptual disturbances, impaired motor coordination, memory deficit, depersonalization, delusions, paranoia – and others. (Diagnostic and Statistical Manual of Mental Disorders (DSM) IV, APA. Washington DC 1994)
Marijuana may cause depression, flashbacks, aggressive feelings and has been associated with loss of motivation.
A history of unemployment or of violent behaviour was associated with more frequent cannabis use.
Marijuana use causes antisocial personality traits and symptoms.
Marijuana use linked to homicide. It is clear that abnormal behaviour induced by the use of psychoactive drugs plays a significant role in violent crimes which are completely unrelated to either drug profits or trafficking. Many of the murderers interviewed for this study stated they felt that marijuana use was a factor in their crime.
Acute Effects of Marijuana smoking on aggression
Researchers have found that THC changes the way in which sensory information gets into and is acted on by the hippocampus. This is a component of the brain’s limbic system that is crucial for learning, memory and the integration of sensory experiences with emotions and motivations. Investigations have shown that THC suppresses neurons in the information-processing system of the hippocampus. In addition researchers have discovered that learned behaviours, which depend on the hippocampus, also deteriorate.