Table 1.

Summary of Studies Included in Analysis

Study#	Study title	Sample sizea	THC doses in mg/kg	Duration of infusion in minutes	Other drugs if tested	THC infusions with PANSS - sample size (n)	Placebo infusions with PANSS - sample size (n)
1	THC response in healthy frequent and infrequent cannabis users	44	0.035 and 0.07	2–5	n/a	87	44
2	Interactions between haloperidol and THC	31	0.0286	20	Haloperidol	31	31
3	Genetics of THC response and interaction with tolcapone	78	0.05	20	Tolcapone	78	78
4	THC effects in people with family history of alcoholism	30	0.018 and 0.036	20	n/a	60	30
5	Electrophysiological effects of THC	33	0.015 and 0.030	10	n/a	66	30
6	Interactions between iomazenil and THC	23	0.015	10	Iomazenil	23	23
7	Interactions between naltrexone and THC	6	0.025	20	Naltrexone	6	6
8	Interactions between physostigmine and THC	6	0.015	10	Physostigmine	6	6
9	Interactions between cannabidiol and THC	29	0.035	20	Cannabidiol	29	29
10	THC effects on information processing	7	0.015 and 0.030	10	n/a	14	7
	Total	287b				400	284

Abbreviations: n/a, not applicable; PANSS, Positive and Negative Syndrome scale.

^a Sample sizes represent participants with complete PANSS information on the 28 items for THC condition in each study.

^b39 individuals participated in more than 1 study, resulting in a total sample size of 287.