Table 3.

The association of age and polarity at onset with manic and depressive episodes in two European bipolar disorder cohorts^a

Episode	AAO					PAO
	n	Estimateb	s.e.	Unadjusted P	Adjusted Pc	n	Estimate	s.e.	Unadjusted P	Adjusted P
Number of manic episodes per illness year	1436	0.11	0.03	7.08 × 10−5	3.54 × 10−4*	1156	−0.42	0.06	4.68 × 10−13	3.74 × 10−12*
Number of depressive episodes per illness year	1231	0.07	0.03	1.93 × 10−2	3.86 × 10−2*	1051	0.12	0.06	4.63 × 10−2	1.85 × 10−1

AAO, age at onset; PAO, polarity at onset; n, total number of participants from the Dutch and German cohorts.

* P < 0.05

^a.The number of manic/depressive episodes was divided by (years of illness) + 1. For secondary analyses of the number of episodes not corrected for the years of illness, see the Supplementary Note 2.

^b.Unstandardised beta coefficient.

^c.After Bonferroni–Holm correction.