A prominent, albeit controversial explanation of the comorbidity between cannabis use and psychiatric morbidity and other behavioral outcomes is that cannabis use directly increase risks of these conditions through causal mechanisms (Figure 1A) that may include the pharmacological properties of the drug itself (Figure 1A1.). For instance, as some of the acute effects of tetrahydrocannabinol (THC), the psychoactive component in cannabis, include psychotic symptoms, some have argued that cannabis use may cause psychosis via enduring alterations in brain regions that are activated during acute cannabis-intoxication (18; 19). However, investigators have argued that a more plausible causal pathway may involve socio-environmental factors (20)(Figure 1A2).
