. Author manuscript; available in PMC: 2015 Feb 2.

Published in final edited form as: Psychophysiology. 2013 Aug 2;50(10):974–982. doi: 10.1111/psyp.12081

Table 1. Frequency of Pathological Substance Use by Drug Class, Onset Group, and Comorbidity.

	Early
	Adolescent	Late Adolescent
Type of PSU	Onset	Onset
Any PSU	134 (66)	273 (170)
PSU-Nicotine	123 (61)	181 (116)
PSU-Alcohol	52 (28)	164 (110)
PSU-Illicit	41 (23)	114 (82)
Classes of PSU met
1 out of 3 classes of PSU	70 (30)	139 (73)
2 out of 3 classes of PSU	46 (26)	82 (56)
3 out of 3 classes of PSU	18 (10)	52 (41)

Note: “PSU-Illicit” includes adolescents that met our study’s criteria for PSU based on the use of Amphetamine, Cannabis, Cocaine, Hallucinogens, Inhalant, Opiate, PCP, or miscellaneous. The number of males in each group is presented in parenthesis.