Table 1.

Descriptive information for substance use at all waves (non-users excluded from continuous variables)

Alcohol Use
			Original metric		Log transformed
	n	%	M	SD	M	SD	Skew	Kurtosis
W1	10	2.58	0.89	0.74	−0.54	1.04	−.31	−1.24
W2	39	10.46	4.46	9.10	−0.02	1.72	.38	.63
W3	80	21.68	5.90	14.63	0.34	1.52	.85	.26
W4	106	28.89	13.63	19.03	1.68	1.46	.06	−1.00
W5	140	39.44	29.01	53.75	1.97	1.74	.22	−.78
W6	173	49.86	42.48	73.12	2.47	1.77	−.12	−.77
W7	209	59.54	236.88	361.89	4.22	1.84	−.29	−.80
Marijuana Use
			Original metric		Log transformed
	n	%	M	SD	M	SD	Skew	Kurtosis
W1*	0	0	–	–	–	–	–	–
W2*	7	1.88	4.86	3.18	1.36	.78	−.64	.26
W3	31	8.40	8.74	10.52	1.58	1.13	.12	−.88
W4	45	12.26	26.13	51.14	1.91	1.65	.53	−.82
W5	53	14.93	49.79	98.08	2.30	1.79	.59	−.55
W6	89	25.65	38.67	81.88	2.15	1.68	.61	−.40
W7	164	46.72	94.61	126.79	2.90	2.20	.00	−1.65

Note. W = Wave;

^*Not included in analysis because of low endorsement; n = number of subjects who used alcohol at each wave; Original metric (alcohol) = average number of drinks per drinking episode × number of drinking episodes per year; Original metric (marijuana) = number times smoked marijuana in past year.