Table 1. Description of the population samples.
| Budapest | Manchester | Budapest+Manchester | Difference between Budapest and Manchester | ||
|---|---|---|---|---|---|
| Gender | |||||
| Female (%) | 624 (69.7%) | 916 (70%) | 1540 (69.9%) | X2=0.017; P=0.897 | |
| Male (%) | 271 (30.3%) | 393 (30%) | 664 (30.1%) | ||
| Age (mean±s.e.m.) | 31.26 (0.355) | 34.04 (0.284) | 32.91 (0.224) | t=−6.153; P<0.001 | |
| MTHFR rs1801133 | |||||
| TT (%) | 122 (13.6%) | 154 (11.8%) | 276 (12.5%) | X2=1.717; P=0.424 | |
| TC (%) | 400 (44.7%) | 602 (46%) | 1002 (45.5%) | ||
| CC (%) | 373 (41.7%) | 553 (42.2%) | 926 (42%) | ||
| MTHFD1L rs11754661 | |||||
| AA (%) | 1 (0.1%) | 10 (0.8%) | 11 (0.5%) | X2=9.914; P=0.007 | |
| GA (%) | 75 (8.7%) | 148 (11.8%) | 223 (10.5%) | ||
| GG (%) | 786 (91.2%) | 1100 (87.4%) | 1886 (89%) | ||
| Rumination score (mean±s.e.m.) | 1.94 (0.016) | 2.25 (0.017) | 2.13 (0.012) | t=−13.104; P<0.001 | |
| BSI depression score (mean±s.e.m.) | 0.56 (0.023) | 1.07 (0.028) | 0.86 (0.020) | t=−13.954; P<0.001 | |
| Lifetime depression | |||||
| Reported (%) | 192 (21.5%) | 734 (56.1%) | 926 (42%) | X2=261.521; P<0.001 | |
| Not reported (%) | 703 (78.5%) | 575 (43.9%) | 1278 (58%) | ||
Abbreviations: BSI, Brief Symptom Inventory; MTHFR, 5,10-methylenetetrahydrofolate reductase.
The Manchester sample shows significantly higher mean age, rumination score and BSI depression score, and higher frequencies of reported lifetime depression and of the MTHFD1L rs11754661 A allele than the Budapest sample.