Table 3. Change in cognition over time.

		Cannabis users		Non-users		F values
		Baseline	3 years	Baseline	3 years	Time	Group	Time x Group
Verbal Memory
	Male	6.82 (2.94)	7.97 (3.26)	6.94 (3.08)	7.70 (3.41)	0.379	0.323	0.387
	Female	8.87 (3.64)	9.73 (3.03)	8.25 (3.17)	9.62 (3.03)	3.725	0.421	1.110
Visual Memory
	Male	19.54 (7.01)	22.08 (7.10)	18.38 (7.78)	21.26 (6.66)	0.343	2.083	0.100
	Female	16.33 (7.90)	17.47 (6.43)	16.37 (6.65)	19.17 (5.84)	0.137	0.372	0.653
Working Memory
	Male	5.45 (1.90)	5.66 (1.67)	5.55 (1.73)	5.85 (1.78)	0.185	0.712	0.008
	Female	5.00 (1.46)	5.00 (1.46)	5.37(1.96)	5.53 (1.73)	0.519	0.749	0.286
Executive Function
	Male	-56.77 (43.91)	-49.13 (40.42)	-59.72 (45.92)	-52.68 (45.24)	1.479	1.107	0.015
	Female	-58.07 (41.54)	-43.43 (29.59)	-69.75 (63.58)	-47.14 (47.32)	4.343*a	0.068	0.524
Processing speed
	Male	5.31 (2.60)	6.95 (3.04)	6.67 (3.31)	7.10 (2.64)	0.366	0.190	8.814*
	Female	6.67 (3.56)	9.00 (3.46)	7.70 (2.56)	9.18 (2.94)	2.297	0.567	0.565
Motor dexterity
	Male	-72.29 (16.20)	-66.48 (14.36)	-78.65 (41.83)	-70.30 (19.67)	3.967*a	5.212*b	0.941
	Female	-74.00 (16.91)	-62.43 (11.13)	-72.85 (23.94)	-67.12 (17.04)	3.677	0.035	0.444
Attention
	Male	72.17 (11.90)	74.29 (10.15)	67.67 (16.02)	69.59 (14.16)	0.172	7.168*c	0.031
	Female	72.33 (8.91)	76.00 (6.73)	65.73 (16.35)	71.24 (11.16)	0.075	1.441	0.053
Global Cognitve Functioning
	Male	1.40 (0.83)	1.22 (0.89)	1.65 (1.15)	1.69 (1.11)	0.318	9.948*c	1.151
	Female	1.27 (1.15)	1.08 (1.34)	1.34 (0.89)	1.20 (0.99)	0.993	0.034	0.097

*: p<0.05.

**: p<0.01.

Covariates were age, years of education and premorbid IQ.

a. Non-users show better performance at 3-year than at baseline

b. Users outperform non-users at 3-year

c. Users outperform non-users at baseline and 3-year.