Table 1

Baseline characteristics stratified by depression status

Major depressive disorder
(n=403 665)
Referent cohort
(n=5 323 986)
P values
Age, median (IQR)37 (24)36 (28)<0.0001
Sex, n (%)<0.0001
 Male140 803 (34.9)2 683 785 (50.4)
 Female262 862 (65.1)2 640 201 (49.6)
Socioeconomic status,* n (%)<0.0001
 Not available21 601 (5.3)442 949 (8.3)
 1 (least deprivation)83 265 (20.6)1 162 250 (21.8)
 276 443 (18.9)1 026 713 (19.3)
 379 639 (19.7)1 028 959 (19.3)
 480 154 (19.8)969 265 (18.2)
 5 (highest deprivation)62 563 (15.5)693 850 (13.0)
Charlson Comorbidity Index, n (%)<0.0001
 0314 298 (77.9)4 328 768 (81.3)
 165 109 (16.1)634 421 (11.9)
 211 956 (3.0)138 337 (2.6)
 34274 (1.0)51 884 (1.0)
 ≥48028 (2.0)170 576 (3.2)
Smoking, n (%)<0.0001
 Not available78 356 (19.4)1 146 709 (21.5)
 Never187 753 (46.5)2 704 033 (50.8)
 Ex-smoker32 384 (8.0)471 910 (8.9)
 Current105 272 (26.1)1 001 334 (18.8)
Obesity, n (%)<0.0001
 Not available171 901 (42.6)2 187 056 (41.1)
 Obese39 755 (9.9)439 087 (8.3)
Anxiety, n (%)<0.0001
 Anxiety90 723 (22.5)170 882 (3.2)
Antidepressant use overall, n (%) 375 075 (92.9)846 882 (15.9)<0.0001
 Atypical antidepressant10 366 (2.6)45 676 (0.9)
 Mirtazapine6372 (1.6)17 365 (0.3)
 Monoamine oxidase inhibitor371 (0.1)397 (0.01)
 Serotonin norepinephrine reuptake inhibitor7848 (1.9)18 215 (0.3)
 Selective serotonin reuptake inhibitor268 557 (66.5)387 548 (7.3)
 Serotonin modulator5795 (1.4)14 384 (0.3)
 Tricyclic antidepressant63 394 (15.7)336 397 (6.3)
Developed Crohn’s disease, n (%)203 (0.1)1589 (0.03)<0.0001
Developed UC, n (%)539 (0.1)4675 (0.1)<0.0001
  • *Socioeconomic status based on the Townsend deprivation quintiles.

  • †Patients could be on more than one antidepressant.