One main finding was that the mean scores on Novelty-Seeking, Persistence, Self-Directedness, Cooperativeness, and Self-Transcendence of cocaine users were different from those of the general population. As has been widely documented in the research literature, Novelty-Seeking is the personality dimension that consistently scores higher in drug-using populations. This suggests that behavioral disinhibition (i.e., sensation-seeking, novelty-seeking, impulsivity, and deviance proneness) is related to substance abuse. In addition to higher scores on Novelty-Seeking, lower scores on Self-Directedness and Cooperativeness, as well as higher scores on Self-Transcendence were related to high severity of substance use. Fifty of the 120 cocaine users were diagnosed with a lifetime Axis I disorder other than substance-use disorder, and 15 of the cocaine users were diagnosed with a lifetime antisocial or borderline personality disorder. Only 18 users did not meet criteria for any DSM-IV disorder. These findings underscore the usefulness in substance-abuse treatment of a phenotype defined according to individual differences in certain personality traits, in severity of cocaine use, and in the presence of psychiatric comorbidity. A total of 120 participants (46 women, mean age of 23.8 years old) were recruited from nonclinical settings in Barcelona, Spain. They were assessed with the Psychiatric Research Interview for Substance and Mental Disorders (PRISM) and the Temperament and Character Inventory-Revised version (TCI-R). 4 tables and 55 references