Purpose: Psychological; to investigate whether personality dimensions, such as novelty seeking, harm avoidance or reward dependence (found in the Tridimensional Personality Questionnaire) are related to ecstasy use, and to discover whether ecstasy users have a distinct psychological profile.

Design: Non-experimental (retrospective) nested between-group design, with initial comparisons between ecstasy users and non-ecstasy users, and subsequent analyses dividing ecstasy users into "experimenters" and "abusers," and non-ecstasy users into polydrug users, cannabis users and non-drug users. All participants completed a measure of personality and a measure of psychiatric symptoms.

Subjects: 43 ecstasy users and 77 non-ecstasy users residing in northeastern Italy, with participants recruited either via snowball sampling or by contacting students attending an area high school. Matching - (Matching not explicitly mentioned, but statistical tests performed) - Ecstasy users and non-ecstasy users matched on age, marital status and education. Criteria for Inclusion - Ecstasy users - Reported having used ecstasy at least once in his or her lifetime. Non-ecstasy users - Never having used ecstasy in his or her lifetime, but use of other drugs permitted. Divisions of both groups made after selection; "experimenters" (approximately 24/43) were those who reported lifetime use of 27.5 tablets or less, and "abusers" (approximately 19/43) as those with a lifetime use of more than 27.5 tablets (Justification for categorization not provided, and the exact number of participants belonging to each category is not reported, only percentages). Polydrug users (10/77) reported using cannabis and other illicit drugs, cannabis users (21/77) reported only using cannabis, but not any other illicit drug, and non-drug users (45/77) did not report any use of illicit drugs.

Drug Use Parameters - Ecstasy users reported a lifetime use of 233 +/- 438.8 tablets, with average dose per use reported as 1.5 +/- 1.1 tablets. No information is provided concerning either duration or frequency of ecstasy use, though statement in the discussion suggests weekly use (4 times per month) to be the mode. Maximum number of tablets used per occasion was 3.6 +/- 6 tablets. Other Drug Use - (presented for ecstasy users only, reported as percentage of experimenters and abusers reporting any lifetime use of each drug listed). Cannabis was used by 95.2% experimenters and 90,5% abusers. Amphetamines used by 14.3% experimenters and 38.1% abusers. Cocaine was used by 47.6% experimenters and 81% abusers. LSD was used by 42.9% experimenters and 90.5% abusers. Ketamine was used by 9.5% experimenters and 23.8% abusers. Poppers were used by 76.2% experimenters and 95.2% abusers. Benzodiazepines were used by 33.3% experimenters and 76.2% abusers. Heroin was used by 4.8% experimenters and 23.8% abusers. "Experimenter" ecstasy users were significantly less likely to use benzodiazepines or poppers than "abuser" ecstasy users (results of 1-way ANOVA), and "experimenters" were marginally less likely to use cocaine than "abusers." Though not provided directly, it is assumed that 100% of all cannabis users, by definition, had used cannabis. No information is provided on drugs used by polydrug user/no ecstasy controls, but they all may have used cannabis and at least one other illicit drug.

Group Demographics and Matched Variables - The authors do not explicitly state any attempt to match ecstasy users with control participants, but statistical analyses were performed on demographic variables; ecstasy users and non-ecstasy users matched on age, marital status and education. Gender, as M/F ratio - Ecstasy users, 34/9, non-ecstasy users, 34/43. Age - Average age for ecstasy users = 20 +/- 3.4 years, and average age for non-ecstasy users = 18 +/- 3.7. Education (presented number of sample with less than or only compulsory education versus those with greater than compulsory education, with years compulsory education not defined, and assumed to be at least 10 years): 38 / 43 ecstasy users had completed no more than compulsory education, and 5/43 ecstasy users had attained more than compulsory education. 67 / 77 non-ecstasy users no more than compulsory education, and 10/77 non-ecstasy users had attained more than compulsory education. Rough approximation, in years of education attained, would be 11 years for ecstasy users and non-ecstasy users is 11.5 years. There is some indication that most or all non-drug users were recruited from the high school.) Experimenters were more likely to be high school students than to be recruited via snowball sampling than abusers. Marital status - 42 ecstasy users were single, and 1 lived with a partner. 75 non-ecstasy users were single and 2 lived with a partner. Other Variables - 14/43 ecstasy users were employed, 2/43 were occasionally employed, 2/43 were unemployed and 25/43 were students. 3/77 non-ecstasy users were employed and 74/77 were students.

Measures: Personality - Measured via the Tridimensional Personality Questionnaire (TPQ), a self-administered instrument with 3 subscales, novelty seeking (NS), harm-avoidance (HA), and reward dependence (RD). It is intended to measure cross-situationally stable traits.

Psychiatric Symptoms - Psychiatric symptoms measured via the SCL-90, a measure of self-reported psychiatric symptoms with 10 separate sub-scales. A global severity index was also calculated.

Drug Use - (for drug-use parameters only) - Author constructed "Questionnaire for the Assessment of the Use of Entactogenic Drugs." The questionnaire has items addressing drug use parameters, drug purchase, acute and sub-acute subjective effects of ecstasy (presumed to be MDMA and congeners). Not all data from this questionnaire presented in this publication.

Analyses: Personality and Psychiatric Symptoms - The Mann-Whitney U test (non-parametric) was performed separately for each TPQ sub-scale score, and all 10 SCL-90 scale scores, plus the global severity index, comparing across ecstasy users and non-ecstasy users. A subsequent analysis, also using Mann-Whitney U, compared ecstasy "experimenters" and "abusers," and also compared ecstasy users only with non-drug user controls. Mann-Whitney U test was also used to compare TPQ and SCL-90 scores across gender (comparative means not provided). A 1-way ANOVA was with drug-use group as a between subjects variable (ecstasy use, other drug use (combination of cannabis users, polydrug users) and non-drug use) was used to analyze the the TQP NS score. P. value is not explicitly stated but appears to be set at p. = 0.05.

Results - Significant Differences Found: Personality - Initial analysis found ecstasy users had higher NS scores than did non-ecstasy users. When divided into "experimenters" and "abusers," ecstasy "abusers" had lower HA scores than "experimenters." NS scores were significantly higher in ecstasy users than in other drug users or non-drug users (result of 1-way ANOVA). Both the HA and RD scale scores were related to participant's gender; authors do not indicate the direction for either gender difference.

Psychiatric Symptoms - Initial analysis found that ecstasy users had higher ratings on the SCL-90 obsessive-compulsive, phobic anxiety, psychoticism and sleep disturbance scales. Ecstsay users differed from non-users on the same 4 SCL-90 scales listed above (obsessive-compulsive, phobic anxiety, psychoticism and sleep disturbance.) Gender differences (not described) were found for SCL-90 somatization, depression, interpersonal sensitivity, phobic anxiety, paranoid ideation and global severity index scores.

Results - No Significant Differences: Personality - Initial analysis found that ecstasy users did not differ from non-ecstasy users on RD or HA scores. Analysis comparing ecstasy-using "experimenters" with "abusers" found that abusers and experimenters did not have significantly different RD or NS scores. There were no gender differences in NS scores.

Psychiatric Symptoms - Ecstasy users and non-ecstasy users had similar ratings on the following SCL-90 scales: Somatisation, depression, interpersonal sensitivity, anxiety, hostility, paranoid ideation and global severity index. Analysis comparing ecstasy "experimenters" and "abusers" found no significant differences between the 2 groups on any SCL-90 scale. No gender differences were found for SCL-90 obsessive compulsive, anxiety or hostility scores.

Overall Effects: When compared with individuals (mostly high school students) who reported no use of ecstasy, people reporting ecstasy use had higher novelty seeking scores. However, their harm avoidance and reward dependence scores were not significantly different from non-ecstasy users. No more differences appeared when people reporting use of other illicit drugs were removed from the control sample. Those who took 27.5 ecstasy tablets or less had higher harm avoidance scores than people who had taken a greater number of tablets. Unspecified gender differences were also found to exist on harm avoidance and reward dependence scores across ecstasy users and non-ecstasy users. When compared for prevalence of psychiatric symptoms as indicated through SCL-90 scores, ecstasy users had higher scores than non-ecstasy users on obsessive-compulsiveness, phobic anxiety, psychoticism and sleep disorders. They did not differ from non-ecstasy users on global severity index. However, there were also gender differences (unspecified) on scores for somatization, interpersonal sensitivity, depression, phobic anxiety, paranoid ideation and global index.

Comments: The authors of this paper sought to use the TPQ to identify a potential personality profile for ecstasy users, and they are the second research team to find higher NS scores for ecstasy users (see Gerra et al. 1998; Gerra et al. 2000). Other studies have found higher psychoticism and phobic anxiety scores in ecstasy users (Daumann et al. 2001; Parrott et al. 2001b; Parrott et al. 2000). However, it should be noted that in one study, higher scores were not significantly different from those in cannabis users (Daumann et al. 2001) and in the other, ecstasy users had higher ratings on other SCL-90 scores as well, including global severity index (Parrott et al. 2001b). It appears that findings vary across publications to a degree suggesting that several variables, such as extent of drug use in general or pre-existing conditions, are involved in the association between these psychiatric symptoms and ecstasy use. Several statistics and demographic variables were not reported in this study, including the exact number of "experimenters" versus "abusers" and the direction of gender differences found with TPQ and SCL-90 scores. Consequently, it is difficult to draw strong conclusions from the findings reported concerning "experimenters" versus "abusers," or any mediating or moderating role of gender in differences on psychometric scores.