Baseline characteristics of the intention-to-treat (ITT) population
| Baseline characteristics | Control (n=172) n (%) | DISCOVER (n=142) n (%) | Overall (N=314) n (%) |
| Age, mean (SD) | 17.2 (0.6) | 17.3 (0.6) | 17.2 (0.6) |
| Gender | |||
| Male | 25 (14.5) | 29 (20.4) | 54 (17.2) |
| Female | 134 (77.9) | 107 (75.4) | 241 (76.8) |
| Other | 13 (7.6) | 6 (4.2) | 19 (6.1) |
| Ethnicity | |||
| White | 86 (50.0) | 72 (50.7) | 158 (50.3) |
| Mixed | 12 (7.0) | 10 (7.0) | 22 (7.0) |
| Asian | 25 (14.5) | 28 (19.7) | 53 (16.9) |
| Black | 31 (18.0) | 22 (15.5) | 53 (16.9) |
| Other/missing | 18 (10.5) | 10 (7.0) | 28 (8.9) |
| Sixth form/college year | |||
| Year 1 | 88 (51.2) | 62 (43.7) | 150 (47.8) |
| Year 2 | 84 (48.8) | 80 (56.3) | 164 (52.2) |
| English as the first language | |||
| No | 19 (11.0) | 19 (13.4) | 38 (12.1) |
| Yes | 153 (89.0) | 123 (86.6) | 276 (87.9) |
| Number of GCSEs passed, mean (SD) | 8.4 (1.8) | 8.4 (1.7) | 8.4 (1.7) |
| Participant IMD, mean (SD) | 4.2 (2.7) | 4.6 (2.9) | 4.4 (2.8) |
| Previously sought help from GP for mental health | |||
| No | 121 (70.3) | 101 (71.1) | 222 (70.7) |
| Yes | 51 (29.7) | 41 (28.9) | 92 (29.3) |
GCSE, General Certificate of Secondary Education; GP, General Practitioner; IMD, Index of Multiple Deprevation.