Table 2 Association between long-term exposure to air pollutants and major depressive disorder (MDD)

PM_2.5, per 5-μg/m³ increase

--

1.92 (1.79, 2.07)

1.16 (1.07, 1.26)

 Q1

3075/880,978

1.00 (Ref.)

1.00 (Ref.)

 Q2

3452/849,441

1.16 (1.11, 1.22)

1.08 (1.03, 1.13)

 Q3

3885/858,381

1.30 (1.24, 1.36)

1.12 (1.06, 1.17)

 Q4

4398/838,285

1.47 (1.40, 1.54)

1.11 (1.06, 1.17)

 P for trend

<0.001

<0.001

PM₁₀, per 10-μg/m³ increase

--

1.30 (1.20, 1.41)

1.00 (0.92, 1.09)

 Q1

3420/879,257

1.00 (Ref.)

1.00 (Ref.)

 Q2

3741/868,525

1.11 (1.06, 1.16)

1.03 (0.98, 1.07)

 Q3

3838/838,579

1.18 (1.12, 1.23)

1.05 (1.00, 1.10)

 Q4

3711/840,723

1.14 (1.08, 1.19)

0.98 (0.94, 1.03)

 P for trend

<0.001

0.610

NO₂, per 10-μg/m³ increase

--

1.15 (1.13, 1.17)

1.00 (0.98, 1.02)

 Q1

3365/914,056

1.00 (Ref.)

1.00 (Ref.)

 Q2

3688/879,294

1.14 (1.09, 1.19)

1.02 (0.98, 1.07)

 Q3

3739/828,930

1.23 (1.17, 1.28)

1.02 (0.98, 1.07)

 Q4

3918/804,805

1.32 (1.26, 1.39)

0.99 (0.94, 1.04)

 P for trend

<0.001

0.695

NO_X, per 20-μg/m³ increase

--

1.15 (1.13, 1.17)

1.02 (1.01, 1.05)

 Q1

3254/911,938

1.00 (Ref.)

1.00 (Ref.)

 Q2

3620/970,880

1.17 (1.11, 1.22)

1.06 (1.01, 1.12)

 Q3

3634/819,160

1.24 (1.19, 1.30)

1.05 (1.00, 1.11)

 Q4

4202/825,106

1.43 (1.36, 1.50)

1.07 (1.02, 1.13)

 P for trend

<0.001

0.017