Table 1.

Demographic data for participants.

	Patients ( n=20)	Controls (n=19)
Age (yrs)	42.15±4.3	39.9±4.5
Education (yrs)	12.07±1.7	14.9±2.9
Gender	20 males	19 males
Cocaine dependence severity	7.26±1.76	0
Alcohol dependence severity	2.68±2.54	0
Marijuana dependence or abuse	2	0
Drug craving score	0~3, 0.28±0.83	0
Cigarette per day	7.67±6.0	0
Smoking duration (yrs)	15.61±12.1	0