• In addition, the review found no consistent evidence that cannabidiol (CBD) moderates the effects of tetrahydrocannabinol (THC - the psychoactive component of cannabis) in healthy volunteers
• Single dose of THC, roughly equivalent to smoking one joint, may induce a variety of psychiatric symptoms associated with schizophrenia and other psychiatric disorders. These effects are larger with intravenous administration than with inhaled administration, while tobacco smokers have fewer symptoms - though the authors stress that further work is needed to test this, and this finding should not be taken as a recommendation to use tobacco to counter the effects of THC.
• These findings highlight the risks of cannabis use, which are highly relevant as medical, societal, and political interest in cannabinoids continues to grow.

Full text article in Lancet Psychiatry - Psychiatric symptons caused by cannabis consituents: a systematic review and meta-analysis