Table 1.
Demographics and substance use of chronic MDMA users and control group.
| Controls (n = 39) | MDMA Users (n = 39) | statistic | p | |
|---|---|---|---|---|
| Age, years | 30.08 (6.74) | 29.92 (6.74) | 0.10 | 0.92 |
| Sex (female / male) | 23/16 | 22/17 | 0.00 | 1.00 |
| Years of school education | 10.03 (1.37) | 10.41 (1.46) | 1.20 | 0.23 |
| Verbal Intelligence | 105.03 (10.62) | 102.87 (10.44) | 0.90 | 0.37 |
| ADHD total score | 10.67 (7.03) | 14.54 (10.51) | 1.91 | 0.060 |
| CESD total score | 10.69 (8.33) | 12.85 (11.58) | 0.94 | 0.35 |
| MDMA | ||||
| Consumed last 6 months (y/n) | 0/39 | 39/0 | 74.05 | <0.001 |
| Dose per week [mg]a | 0.00 (0.00) | 103.05 (137.58) | 4.68 | <0.001 |
| Occasions per week a | 0.00 (0.00) | 0.36 (0.29) | 7.66 | <0.001 |
| Years of use | 0.00 (0.00) | 9.27 (6.14) | 9.44 | <0.001 |
| Cumulative dose lifetime [g] | 0.02 (0.10) | 95.02 (156.42) | 3.79 | <0.001 |
| Cumulative dose lifetime [tablets]b | 0.12 (0.64) | 633.46 (1042.83) | – | – |
| Days since last consumption c | – | 22.56 (18.54), n = 39 | – | – |
| Positive urine testing (y/n) | 0/39 | 0/39 | – | – |
| Hair analysis [pg/mg] d | 0.00 (0.00) | 773.00 (892.53) | 2.32 | 0.023 |
| Nicotine | ||||
| Consumed last 6 months (y/n) | 22/17 | 26/13 | 0.49 | 0.49 |
| Cigarettes per day | 3.09 (5.42) | 4.56 (6.45) | 1.09 | 0.28 |
| Years of use | 7.46 (7.68) | 10.15 (8.83) | 1.44 | 0.15 |
| Alcohol | ||||
| Consumed last 6 months (y/n) | 34/5 | 39/0 | 3.42 | 0.064 |
| Dose per week [g] a | 0.09 (0.13) | 0.15 (0.18) | 1.67 | 0.099 |
| Occasions per week a | 2.12 (1.72) | 2.21 (1.83) | 0.23 | 0.82 |
| Years of use | 12.59 (7.43) | 13.98 (7.13) | 0.84 | 0.40 |
| Cumulative dose lifetime [kg] | 98.20 (140.60) | 149.54 (208.45) | 1.28 | 0.21 |
| Days since last consumption c | 8.03 (24.58), n = 34 | 14.21 (29.73), n = 39 | 0.96 | 0.34 |
| Cannabis | ||||
| Consumed last 6 months (y/n) | 9/30 | 23/16 | 8.96 | 0.003 |
| Dose per week [g] a | 0.05 (0.14) | 0.28 (0.76) | 1.86 | 0.067 |
| Occasions per week a | 0.23 (0.72) | 0.64 (1.37) | 1.66 | 0.10 |
| Years of use | 4.90 (6.79) | 9.26 (7.46) | 2.70 | 0.009 |
| Cumulative dose lifetime [g] | 233.33 (620.40) | 818.42 (1277.29) | 2.57 | 0.012 |
| Days since last consumption c | 34.11 (58.06), n = 9 | 25.00 (30.92), n = 23 | 0.58 | 0.57 |
| Positive urine testing (y/n) | 2/37 | 1/38 | 0.00 | 1.00 |
| Hair analysis [pg/mg] d | 0.00 (0.00) | 0.00 (0.00) | 2.47 | 0.016 |
| Amphetamine | ||||
| Consumed last 6 months (y/n) | 0/39 | 21/18 | 26.07 | <0.001 |
| Dose per week [g] a | 0.00 (0.00) | 0.04 (0.09) | 2.69 | 0.009 |
| Occasions per week a | 0.00 (0.00) | 0.13 (0.26) | 3.08 | 0.003 |
| Years of use | 0.00 (0.00) | 4.84 (7.08) | 4.27 | <0.001 |
| Cumulative dose lifetime [g] | 0.01 (0.04) | 115.27 (361.44) | 1.99 | 0.050 |
| Days since last consumption c | – | 39.14 (45.18), n = 21 | – | – |
| Positive urine testing (y/n) | 0/39 | 0/39 | – | – |
| Hair analysis [pg/mg] d | 0.00 (0.00) | 18.00 (26.69) | 2.53 | 0.013 |
| Cocaine | ||||
| Consumed last 6 months (y/n) | 3/36 | 26/13 | 26.57 | <0.001 |
| Dose per week [g] a | 0.00 (0.00) | 0.10 (0.21) | 2.79 | 0.007 |
| Occasions per week a | 0.00 (0.01) | 0.20 (0.43) | 2.84 | 0.006 |
| Years of use | 0.00 (0.00) | 4.33 (6.28) | 4.31 | <0.001 |
| Cumulative dose lifetime [g] | 0.03 (0.10) | 41.97 (89.61) | 2.92 | 0.005 |
| Days since last consumption c | 56.33 (34.24), n = 3 | 60.65 (61.46), n = 26 | 0.12 | 0.91 |
| Positive urine testing (y/n) | 0/39 | 1/38 | 0.00 | 1.00 |
| Hair analysis [pg/mg] d | 0.00 (0.00) | 167.00 (247.59) | 1.18 | 0.24 |
| Ketamine | ||||
| Consumed last 6 months (y/n) | 0/39 | 14/25 | 14.71 | <0.001 |
| Dose per week [g] a | 0.00 (0.00) | 0.01 (0.03) | 2.22 | 0.029 |
| Occasions per week a | 0.00 (0.00) | 0.05 (0.13) | 2.21 | 0.030 |
| Years of use | 0.00 (0.00) | 0.20 (0.75) | 1.69 | 0.096 |
| Cumulative dose lifetime [g] | 0.00 (0.00) | 1.97 (5.25) | 2.35 | 0.022 |
| Days since last consumption c | – | 60.14 (60.50), n = 14 | – | – |
| Hair analysis [pg/mg] d | 0.00 (0.00) | 0.00 (0.00) | 2.39 | 0.019 |
Values reflect mean and standard deviations, except that for hair residuals the median and median absolute deviation are shown due to a highly right-skewed distribution.
Statistical tests: independent t-tests for quantitative data, chi-squared test for frequency data; significant p-values are shown in bold.
within the past 6 months. In this case, sample size (n) is shown.
a
During the last 6 months.
b
In 150 mg tablets.
c
Days since last consumption is an average including only persons who reported to have used the substance.
d
Hair residuals reflect sum score of respective substance and its metabolites as quantified via forensic hair toxicology.