All the students were administered the Zuckerman Sensation Seeking Scale (SSS), the Eysenck Personality Questionnaire (EPQ), the Buss-Durkee Hostility Inventory (BDHI), and the Parental Bonding Instrument (PBI). Lifetime alcohol use was reported by 80.5 percent of the students; "alcohol abuse" was reported by 37.7 percent, cannabis use by 26.2 percent, ecstasy use by 2.8 percent, heroin use by 3.8 percent, and cocaine use by 8.3 percent. Male students significantly outnumbered female students for alcohol use, "alcohol abuse," and ecstasy use, but not for the use of cannabis, heroin, and cocaine. Illicit drug use and "alcohol abuse" (polydrug users) were associated with higher sensation seeking as measured by the SSS, social coping impairment as measured by the EPQ, direct aggressiveness as measured by the BDHI, poor school achievements, and lower perception of parental care as measured by the PBI. Compared with abstinent students, increased levels of aggressiveness and sensation-seeking were found both in minimal experimenters with drugs and alcohol and habitual users. Minimal experimenters scored higher than abstinent students on the EPQ for social coping impairment, but they scored lower on this trait than habitual users. The perception of parental care was lower in habitual users, but not in minimal experimenters compared to abstinent subjects. Pearson inverse correlation was found between PBI scores and EPQ maladaptation and BDHI aggressiveness. The authors conclude that this preliminary pilot study indicates that temperamental traits, personality changes, and a perception of weak parental care may be linked to an early tendency to use substances. They advise that longitudinal studies will be required to evaluate the possible role of the associations reported in this study, as well as to allow for the design of interventions that enhance protective factors for youth at risk for serious substance use. 8 tables and 42 references