Table 1.
Demographics of Patients, According to History of Cannabis Use
| History of Cannabis Use (n = 256) |
No History of Cannabis Use (n = 154) |
Test Statistic | P Value | |
|---|---|---|---|---|
| Mean (SD); median age at onset of psychosis (y) | 28.2 (8.0); 27.1 | 31.4 (9.9); 30.0 | z = 3.13 | .001 |
| Gender, n (%) | ||||
| Male | 194 (75.9) | 81 (52.5) | χ2 (1) = 24.5 | <.001 |
| Female | 62 (24.1) | 73 (47.5) | ||
| Ethnicity | ||||
| White | 88 (34.1) | 42 (26.9) | χ2 (3) = 17.3 | .001 |
| Black African | 93 (36.4) | 39 (25.6) | ||
| Black Caribbean | 47 (18.2) | 56 (35.9) | ||
| Other | 28 (11.2) | 17 (11.6) | ||
| Other illicit drugs use | ||||
| Never | 131 (51.3) | 148 (96.7) | χ2 (1) = 98.6 | <.001 |
| Yes | 125 (48.7) | 6 (3.3) | ||
| Lifetime tobacco smoking | ||||
| Never | 25 (10.1) | 100 (65.0) | χ2 (1) = 128.4 | <.001 |
| Yes | 231 (89.9) | 54 (35.0) | ||
Note: P values from Mann-Whitney U and chi-squared tests.