Table 1.
Within-person study samples and designs involving healthy individuals receiving THC and placebo
| Sample size | Mean age (SD), years | Male: female | Randomised order | Route | Dose | Placebo condition | Scale and subscales | Time between dose and measurement | |
|---|---|---|---|---|---|---|---|---|---|
| Barkus et al (2011)6 | 9 | 26·3 (4·2) | 9:0 | Yes | Intravenous | 2·5 mg | 2·5% ethanol plus saline | PANSS: positive and negative | 30 min |
| Bhattacharyya et al (2015)12 | 36 | 26·0 (5·6) | 36:0 | Yes | Oral | 10 mg | Matched placebo–capsule | PANSS: total and positive | 120 min |
| D'Souza et al (2012)16 | 26 | 25·9 (7·8) | 17:9 | Yes | Intravenous | 0·03 mg/kg | Ethanol* | PANSS: total, positive, and negative | 10 mins |
| D'Souza et al (2004)5 | 18 | 29 | 10:5 | Yes | Intravenous | 5 mg | Ethanol* | PANSS: positive and negative | 10 min positive; 80 min negative |
| D'Souza et al (2008)14 | 20 | 24·9 (7·0) | 14:6 | Yes | Intravenous | 5 mg | Ethanol* | PANSS: total, positive, and negative | 15 min |
| D'Souza et al (2009; low cannabis use sample)15† | 14 | 25·9 (8·0) | 11:3 | No | Intravenous | 0·0286 mg/kg | Matched vehicle* | PANSS: positive | 15 min |
| D'Souza et al (2009; high cannabis use sample)15† | 9 | 22·7 (2·8) | 9:0 | No | Intravenous | 0·0286 mg/kg | Matched vehicle* | PANSS: positive | 15 min |
| Morrison et al (2009)8 | 21 | 28 (6) | 21:0 | Yes | Intravenous | 2·5 mg | Normal saline | PANSS: positive | 30 min |
| Morrison et al (2011)9 | 16 | 26 (6) | 7:9 | Yes | Intravenous | 1·25 mg | Normal saline | PANSS: positive and negative | 30 min |
| Ranganathan et al (2012)10 | 26 | 27·1 (7·6) | 26:4 | No | Intravenous | 1·89 mg | Vehicle* | PANSS: positive and negative | 65 min |
| Bhattacharyya et al (2009),11 Bhattacharyya et al (2012),42 Fusar-Poli et al (2009)43 | 15 | 26·7 (5·7) | 15:0 | Yes | Oral | 10 mg | Flour capsule | PANSS: positive and negative | 120 min |
| Radhakrishnan et al (2015)44 | 23 | 25·4 (7·4) | 21:0 | Yes | Intravenous | 1·21 mg | Ethanol vehicle* | PANSS: positive, negative, general, and total | 70 min |
| Liem-Moolenaar et al (2010)18 | 11 | 24·1 (6·7) | 11:0 | Yes | Inhaled | 2 mg, 4 mg, 6 mg | Matching placebo | PANSS: total, positive, and negative | 40 min after last dose |
| Kleinloog et al (2012)17 | 32 | 22·3 (3·18) | 32:0 | Yes | Inhaled | 2 mg, 4 mg, 6 mg | Placebo THC | PANSS: total, positive, and negative | 36 min after last dose |
| Morgan et al (2018)7 | 48 | 21·7 (1·8) | 34:14 | Yes | Inhaled | 8 mg | Ethanol vehicle | BPRS: positive and negative | Not recorded |
| Bossong et al (2009)13 | 7 | 21·9 (2·7) | 7:0 | Yes | Inhaled | 8 mg | Ethanol vehicle | BPRS: total and positive | 21 min |
BPRS=Brief Psychiatric Rating Scale. PANSS=Positive and Negative Syndrome Scale. THC=Δ9-tetrahydrocannabinol.
*
2 mL 190 proof ethanol vehicle.
†
Two independent samples from the same study.