Table 3.
Rates and patterns of cannabis use over lifetime by group
| Cannabis scale | CHR (n = 732) | Controls (n = 276) | Statistics | p |
|---|---|---|---|---|
| Mean age first tried, years (s.d)a | 15.7 (2.82) | 16.6 (2.71) | t = 2.86 | 0.004 |
| Mean number of times used in lifetime (s.d.)b | 125.5 (124.90) | 63.0 (100.15) | t = 4.82 | <0.001 |
| Ever smoked/used, yes | 404 (55.2) | 110 (39.9) | χ2 = 18.98 | <0.001 |
| Currently using | 238 (32.4) | 81 (29.1) | χ2 = 9.29 | <0.01 |
| Past use only | 164 (22.3) | 27 (9.7) | ||
| Missing | 333 (45.3) | 170 (61.2) | ||
| Use frequency for current users | ||||
| Every day | 21 (2.9) | 2 (0.7) | χ2 = 9.50 | 0.22 |
| Once/twice per week | 78 (10.6) | 10 (3.6) | ||
| Once/twice per month to once/twice per year | 79 (10.7) | 23 (8.3) | ||
| Not applicable | 126 (17.1) | 35 (12.6) | ||
| Missing | 431 (58.7) | 208 (74.8) | ||
| Environment for current users | ||||
| Socially | 324 (44.1) | 100 (36.0) | χ2 = 11.01 | 0.001 |
| Alone | 64 (8.7) | 4 (1.4) | ||
| Missing | 347 (47.2) | 174 (62.6) | ||
| Time of use for current users | ||||
| During the day | 48 (6.5) | 4 (1.4) | χ2 = 19.21 | <0.001 |
| During the evening | 212 (28.8) | 80 (28.8) | ||
| Frequently during the day and evening | 141 (19.2) | 21 (7.6) | ||
| Missing | 334 (45.4) | 173 (62.2) |
Data are given as number of participants (percentage) unless otherwise indicated.
CHR, Clinical high risk; s.d., standard deviation.
a
Excludes participants who had never used cannabis.
b
Excludes never-users.