Table 1

Cox regression analysis of factors associated with mania/bipolar disorder (n=21 012)

FactorGroupNumber in sample (%)Incidence rate of mania/bipolar disorder (per 1000 person-years)Association with mania/bipolar disorder
UnadjustedAdjusted model*
HR (95% CI)p ValueHR (95% CI)p Value
Age (years)16–254586 (21.8)10.10.80 (0.67 to 0.96)0.020.84 (0.70 to 1.01)0.06
26–355406 (25.7)12.3ReferenceReference
36–455353 (25.5)11.20.92 (0.78 to 1.09)0.340.90 (0.76 to 1.07)0.23
46–553798 (18.1)10.70.86 (0.71 to 1.04)0.120.84 (0.70 to 1.02)0.07
56–651869 (8.9)8.30.68 (0.52 to 0.88)0.0040.65 (0.50 to 0.85)0.002
GenderFemale12 767 (60.8)11.1ReferenceReference
Male8245 (39.2)10.50.94 (0.83 to 1.07)0.340.94 (0.83 to 1.07)0.35
Prior antidepressant treatmentMAOi37 (0.2)14.11.44 (0.46 to 4.48)0.531.20 (0.38 to 3.79)0.76
Mirtazapine1977 (9.4)13.71.29 (1.07 to 1.57)0.0091.17 (0.96 to 1.43)0.11
SSRI7468 (35.5)13.21.38 (1.22 to 1.57)<0.0011.34 (1.18 to 1.52)<0.001
TCA993 (4.7)13.11.25 (0.96 to 1.62)0.091.12 (0.86 to 2.58)0.39
Trazodone160 (0.8)19.11.80 (1.06 to 3.05)0.031.51 (0.88 to 2.58)0.14
Venlafaxine1184 (5.6)14.91.46 (1.17 to 1.83)0.0011.35 (1.07 to 1.70)0.01
Duloxetine248 (1.2)13.81.27 (0.77 to 2.12)0.351.10 (0.66 to 1.83)0.73
Other antidepressant101 (0.5)13.71.36 (0.65 to 2.86)0.421.05 (0.49 to 2.25)0.90
  • *Results adjusted for all the factors reported in this table.

  • MAOi, monoamine-oxidase inhibitor; SSRI, selective serotonin reuptake inhibitor; TCA, tricyclic antidepressant.