Table 1.

Recent Studies Assessing the Effects of THC on Anxiety in Humans

Citation	Participants	THC Dose/Route	Anxiety Outcome Measures	Anxiety Effects	Main Findings	Sex Differences
Spindle et al. 2018 [23]	Healthy adults (n=17), no past month cannabis use	10mg, 25mg THC vs placebo; vaporized and smoked	VAS anxious and/or nervous, heart racing, restless, relaxed, paranoid	↑	Both 10mg and 25mg doses (both inhalation methods) increased mean ratings of heart racing relative to placebo. The 25mg dose (both inhalation methods) also increased mean ratings of anxious and/or nervous relative to placebo.	Not assessed
Sholler et al. 2021 [24]	Healthy adults (n=50), no past month cannabis use	Low dose (5mg, 10mg) and high dose (20mg, 25mg) THC vs placebo; oral and vaporized	VAS anxious and/or nervous, heart racing, restless, relaxed	↑	Dose-dependent increase observed in VAS ratings of anxious/nervous, heart racing, and restless	VAS ratings of anxious/nervous, heart racing, and restless were significantly higher for female versus male participants, after controlling for body weight and peak blood cannabinoid concentrations
Bassir Nia et al. 2022 [25]	Healthy adults (n=42), minimal cannabis use (~90% no use in past month)	0.015 mg/kg, 0.03 mg/kg THC vs placebo; IV	VAS anxious	↑	Significant main effect observed for dose on VAS scores for anxious	ns
Arkell et al. 2022 [26]	Healthy adults (n=40), occasional cannabis use (<2 times/week and >10 lifetime exposures)	13.75mg THC (with and without 13.75 mg CBD) vs placebo; vaporized	VAS anxious	↑	Significant main effect of condition observed for VAS ratings for anxious	ns
Pabon et al. 2022 [27]	Healthy adult women (n=37), occasional cannabis use (>4 lifetime uses and <11 past month uses)	7.5mg, 15mg THC vs placebo; oral	POMS anxiety subscale	↑	Significant increase in anxiety observed for 15mg dose relative to placebo.	N/A
Matheson et al. 2020 [28]	Healthy adults (n=91), regular cannabis use (1–4x/week)	750mg cannabis cigarette with 12.5% THC vs placebo; smoked ad libitum for 10 mins	POMS anxiety subscale	-	No main effect of condition on anxiety	Significant effects of sex observed for amount smoked, estimated THC dose, THC concentration, and AUC of THC, with females displaying less consumption and exposure. No significant sex differences in anxiety observed.

Abbreviations: ↑=anxiogenic; -=no effect; AUC=area under the curve; CBD=cannabidiol; DEQ=drug effects questionnaire; IV=intravenous; mg=milligrams; ns=not significant; N/A=not applicable; POMS=Profile of Mood States; THC= Delta-9-tetrahydrocannabinol; VAS=visual analogue scale.