Table 1.

Sociodemographic and health characteristics of individuals in the training set patient group (first-episode MDD patients), the extrapolation test set patient group (subthreshold symptomatic individuals who developed MDD within two or four years) and the shared reference group (subthreshold symptomatic individuals who did not develop MDD within four years)

	Shared reference group	Patient group
		Training set	Extrapolation test set
N	86	86	37
Sex % (male/female)	35/65	48/52	32/68
Age (years)	37.8 (14.1)	41.8 (12.2)	38.5 (14)
Body mass index (kg/m2)	23.8 (4.4)	26.7 (6)	25.6 (5)
Education, % (basic/intermediate/high)	8/42/50	6/67/27	3/59/38
Physical activity, % (low/moderate/high)	23/48/29	30/44/26	27/41/32
Smoking, % (yes/no)	31/69	38/62	32/68
Alcohol abuse, % (yes/no)	21/79	40/60	19/81
Weekly alcohol consumption (number of drinks per week)	8 (11)	6.8 (11)	6.3 (7.4)
Recreational drug use (past month), % (yes/no)	7/93	8/92	8/92
Partner, % (yes/no)	69/31	57/43	70/30
Children, % (yes/no)	44/56	48/52	51/49
Employment, % (employed/unemployed/retired/occupationally disabled)	77/17/2/3	60/17/2/20	65/30/0/5
Absent from work due to health problems (past 6 months), % (yes/no/not applicable)	43/35/22	41/21/38	35/32/32
Childhood life event index score	0.3 (0.5)	0.2 (0.5)	0.2 (0.5)
Childhood trauma index score	0.5 (0.9)	1 (1.3)	0.8 (1.1)
Number of negative life events (past year)	1 (1)	1 (1.1)	0.9 (1)
Family history, % (yes/no)	73/27	87/13	84/16
Heart disease, % (yes/no)	1/99	5/95	5/95
Diabetes, % (yes/no)	3/97	6/94	11/89
Other chronic disease, % (yes/no)	26/74	40/60	22/78
Anti-inflammatory drug, % (yes/no)	2/98	8/92	8/92
Heart medication, % (yes/no)	10/90	23/77	8/92
IDS30 total score	14.9 (7.4)	37.4 (11.5)	20.2 (8.8)

IDS inventory of depressive symptomatology, MDD major depressive disorder

Numerical features are shown as the mean (standard deviation)