This comment made me curious and I did some googling for studies on the anxiogenic (anxiety-increasing) effects of THC. Some interesting resuts: THC's anxiety

This comment made me curious and I did some googling for studies on the anxiogenic (anxiety-increasing) effects of THC. Some interesting resuts: THC's anxiety inducing effects are (at least in part) caused by CB! receptor activity in the right amygdala. "Fourteen healthy males were studied with fMRI twice, one month apart, following an oral dose of either delta-9-THC (10 mg) or placebo, while they performed a fear-processing task. Baseline availability of the CB1 receptor was studied using PET with [11C]MePPEP, a CB1 inverse agonist radioligand. Relative to the placebo condition, delta-9-THC induced anxiety and modulated right amygdala activation while processing fear. Both these effects were positively correlated with CB1 receptor availability in the right amygdala. These results suggest that the acute effects of cannabis on anxiety in males are mediated by the modulation of amygdalar function by delta-9-THC and the extent of these effects are related to local availability of CB1 receptors." https://www.nature.com/articles/s41598-017-14203-4 https://www.nature.com/articles/s41598-017-14203-4 Would be interested to study if there is a difference in fear response in sober thc users and non-users. Does 'tolerance' of THC entail amygdalar CB1 downregulation? Does this have measurable effects besides intoxication-related anxiety? --- Anxiogenic effects in rats are greater in adults than adolescents https://www.ncbi.nlm.nih.gov/pubmed/17211649 https://www.ncbi.nlm.nih.gov/pubmed/17211649 --- "Guiaol, eucalyptol, γ-terpinene, α-phellandrene, 3-carene, and sabinene hydrate all have significant correlations with decreased anxiolytic activity." (Certain strains may have constituents which increase anxiety - many of these have distinctive smells) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6204402/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6204402/ --- CBD is widely regarded as safe - this study raises some concern. Could chronic CBD use could possible cause upregulation of amygdalar CB1? Anxiogenic-like effects of chronic cannabidiol administration in rats https://www.researchgate.net/publication/51798464_Anxiogenic-like_effects_of_chronic_cannabidiol_administration_in_rats https://www.researchgate.net/publication/51798464_Anxiogenic...