TABLE 1.

Association of covariates and cannabis use and bipolar disorder in northern Finland birth cohort 1986

				Cannabis use frequency					Bipolar disorder
	Total n	n = 6325		No cannabis use n = 5973		Once or more n = 352		P‐value	No bipolar disorder n = 6259		Bipolar disorder n = 66		P‐value
		n	%	n	%	n	%		n	%	n	%
Sex	6325
Male		3089	48.8	2929	49.0	160	45.5	0.191	3074	49.1	15	22.7	< 0.001
Female		3236	51.2	3044	51.0	192	54.5		3185	50.9	51	77.3
Family structure	5413
Divorced		1102	20.4	1004	19.6	98	33.4	< 0.001	1085	20.3	17	29.3	0.089
Intact		4311	79.6	4116	80.4	195	66.6		4270	79.7	41	70.7
Parental education	5504
Less than 12 years		3382	61.4	3207	61.6	175	58.3	0.255	3349	61.5	33	57.9	0.580
12 years or more		2122	38.6	1997	38.4	125	41.7		2098	38.5	24	42.1
Cannabis use	6325
No		5973	94.4	5973	100.0	0	0.0	–	5918	94.6	55	83.3	0.001 a
Yes		352	5.6		0.0	352	100.0		341	5.4	11	16.7
Other illicit drug use	6299
No		6268	99.5	5942	99.9	326	92.9	< 0.001 a	6204	99.5	64	97.0	0.041 a
Yes		31	0.5	6	0.1	25	7.1		29	0.5	2	3.0
Alcohol intoxication 10 ≥ times past year	6167
No		5024	81.5	4910	84.4	114	32.9	< 0.001	4986	81.7	38	59.4	< 0.001
Yes		1143	18.5	910	15.6	233	67.1		1117	18.3	26	40.6
Parental psychiatric disorder	6325
No		4046	64.0	3836	64.2	210	59.7	0.083	4017	64.2	29	43.9	0.001
Yes		2279	36.0	2137	35.8	142	40.3		2242	35.8	37	56.1
Daily smoking	5853
No		5134	87.7	4960	89.7	174	54.2	< 0.001	5089	87.9	45	70.3	< 0.001
Yes		719	12.3	572	10.3	147	45.8		700	12.1	19	29.7
YSR total		Mean	SD	Mean	SD	Mean	SD	< 0.001 b	Mean	SD	Mean	SD	< 0.001 b
		26.5	15.6	25.9	15.2	36.2	19.0		26.3	15.5	37.2	17.6

^a Fisher's exact test;

^b Mann–Whitney U‐test. YSR = Youth Self Report.