Table 1.
Demographic data and pattern of cocaine use.
| Baseline (t1) | 1-year follow-up (t2)m | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Controls (n = 48) | Cocaine Increaser (n = 19) | Cocaine Decreaser (n = 19) | F/χ²/T | df, dferr | p | Controls (n = 48) | Cocaine Increaser (n = 19) | Cocaine Decreaser (n = 19) | F/χ²/T | df, dferr | p | |
| Age, years | 30.3 (8.9) | 31.5 (9.4) | 31.4 (8.3) | .20a | 2,83 | .82 | ||||||
| Sex (f/m) | 16/32 | 3/16 | 5/14 | 2.11b | 2 | .35 | ||||||
| Verbal IQ (MWT-B)d | 107.6 (10.0) | 102.9 (9.7) | 103.8 (7.1) | 2.20a | 2,83 | .12 | ||||||
| Education, years | 10.8 (1.8) | 10.4 (1.8) | 10.0 (1.5) | 1.30a | 2,83 | .28 | ||||||
| ADHD-SR score (0-22) | 7.7 (5.2) | 13.5 (9.4)** | 14.1 (6.8)** | 8.83a | 2,83 | <.001 | ||||||
| ADHD DSM IV (y/n)e | 0/48 | 4/15 | 3/16 | 7.02b | 2 | .03 | ||||||
| Weeks between t1 and t2 | 58.2 (10.1) | 59.3 (12.1) | 61.9 (14.5) | .69a | 2,83 | .50 | ||||||
| BDI score (0–63) | 3.5 (3.3) | 7.3 (8.0)* | 8.7 (6.5)** | 7.53a | 2,83 | <.001 | ||||||
| BDI depression (y/n)g | 0/48 | 1/18 | 1/18 | 2.59b | 2 | .27 | ||||||
| Cocaine | ||||||||||||
| Times per weekh | – | 1.6 (1.8) | 1.0 (1.3) | 1.17c | 36 | .25 | – | 1.1 (0.8) | 0.3 (0.3) | 3.85c | 36 | <.001 |
| Grams per weekh | – | 2.0 (2.5) | 1.7 (2.3) | .41c | 36 | .68 | – | 1.6 (2.5) | 0.4 (0.4) | 2.18c | 36 | .04 |
| Years of use | – | 7.0 (5.5) | 8.2 (5.4) | .68c | 36 | .50 | – | 8.9 (5.4) | 9.7 (5.2) | .45c | 36 | .65 |
| Age of cocaine onset | – | 24.5 (8.1) | 23.1 (5.2) | .61c | 36 | .54 | ||||||
| Max. dose (g/day)k | – | 4.7 (4.4) | 5.9 (6.4) | .71c | 36 | .48 | – | 3.7 (2.5) | 3.1 (2.8) | .63c | 36 | .53 |
| Cumulative dose (g)k | – | 1182 (1635) | 3698 (8585) | 1.25c | 36 | .22 | – | 91 (119) | 49 (89) | 1.25c | 36 | .22 |
| Last consumption (days) | – | 18.5 (25.1) | 16.8 (14.6) | .29c | 36 | .77 | – | 7.0 (6.3) | 81.4 (145.1) | 2.23c | 36 | .03 |
| Cocaine craving (0–70)i | – | 19.8 (9.5) | 17.7 (7.2) | .79c | 36 | .44 | – | 20.5 (10.8) | 15.8 (6.2) | 1.66c | 36 | .11 |
| Hair analysis (ng/mg)l | ||||||||||||
| Cocainetotal | – | 10.3 (29.2) | 14.9 (32.2) | .46c | 36 | .65 | – | 40.7 (76.1) | 4.2 (8.2) | 2.08c | 36 | .05 |
| Cocaine | – | 8.2 (23.3) | 11.4 (23.9) | .42c | 36 | .68 | – | 31.7 (56.5) | 3.1 (5.9) | 2.19c | 36 | .03 |
| Benzoylecgonine | – | 1.9 (5.5) | 3.1 (7.6) | .58c | 36 | .56 | – | 8.3 (19.6) | 1.0 (2.2) | 1.62c | 36 | .11 |
| Cocaethylene | – | 1.0 (2.8) | 0.9 (2.8) | .11c | 36 | .91 | – | 1.2 (2.1) | 0.3 (1.0) | 1.56c | 36 | .13 |
| Norcocainet | – | 0.2 (0.5) | 0.4 (0.8) | .83c | 36 | .41 | – | 0.6 (1.4) | 0.1 (0.1) | 1.71c | 36 | .10 |
| Urine toxicology (n/p)k | 48/0 | 14/5 | 16/3 | .63b | 1 | .43 | 48/0 | 7/12 | 18/1 | 14.15b | 1 | <.001 |
| Alcohol n | ||||||||||||
| Grams per weekh | 119.9 (136.8) | 169.4 (129.2) | 155.3 (146.4) | 1.07a | 2,83 | .35 | 104.3 (88.6) | 259.7 (244.5)*** | 127.4 (141.4)° | 7.71a | 2,83 | <.001 |
| Years of use | 13.3 (8.8) | 13.7 (7.6) | 12.0 (7.3) | .23a | 2,83 | .79 | 14.0 (8.7) | 14.8 (7.5) | 12.6 (7.9) | .34a | 2,83 | .71 |
| Nicotine n | ||||||||||||
| Smoking (y/n)f | 37/11 | 14/5 | 14/5 | .13b | 2 | .94 | 40/8 | 15/4 | 13/6 | 1.83b | 2 | .40 |
| Cigarettes per dayh | 8.7 (8.7) | 12.8 (11.2) | 9.5 (8.2) | 1.38a | 2,83 | .26 | 8.2 (8.7) | 13.4 (12.0) | 8.2 (7.8) | 2.31a | 2,83 | .11 |
| Years of use | 9.3 (8.3) | 10.4 (8.9) | 12.7 (10.3) | .95a | 2,83 | .39 | 10.5 (8.8) | 12.5 (8.6) | 12.6 (9.9) | .56a | 2,83 | .57 |
| Cannabis n | ||||||||||||
| Grams per weekh | 0.6 (1.6) | 3.3 (8.9) | 1.2 (2.3) | 2.38a | 2,83 | .10 | 0.5 (1.6) | 2.1 (4.6) | 1.1 (2.7) | 2.28a | 2,83 | .11 |
| Years of use | 4.5 (4.9) | 9.5 (8.5)* | 10.1 (9.7)* | 5.92a | 2,83 | .004 | 4.6 (5.9) | 10.5 (9.8)* | 8.6 (9.7) | 4.64a | 2,83 | .01 |
| Cumulative dose (grams) | 980 (3985) | 3199 (5899) | 2606 (6359) | 1.61a | 2,83 | .21 | 53.4 (180) | 217.8 (526.5) | 84.7 (189.6) | 2.15a | 2,83 | .12 |
| Last consumption (days)j | 39.3 (1.6);n = 22 | 10.0 (0.4);n = 14 | 25.4 (1.1);n = 12 | 2.19a | 2,45 | .12 | 36.5 (1.5);n = 22 | 9.7 (0.4);n = 13 | 50.8 (2.1);n = 10 | 1.20a | 2,42 | .31 |
| Urine toxicology (n/p)k | 42/6 | 15/4 | 14/5 | 2.03b | 2 | .36 | 42/6 | 7/12 | 15/4 | 18.61b | 2 | <.001 |
| Amphetamine n | ||||||||||||
| Grams per weekh | 0.0 (0.1) | 0.1 (0.1)** | 0.0 (0.1) | 5.18a | 2,83 | .008 | 0.0 (0.0) | 0.1 (0.2)** | 0.0 (0.1) | 5.89a | 2,83 | .004 |
| Years of use | 0.0 (0.0) | 3.3 (4.0)*** | 1.3 (3.1)° | 13.73a | 2,83 | <.001 | 0.1 (0.5) | 3.2 (4.9)** | 2.7 (5.5)* | 7.46a | 2,83 | .001 |
| Cumulative dose (grams) | 0.0 (0.1) | 56.0 (177.6)* | 16.2 (35.9) | 2.99a | 2,83 | .06 | 0.0 (0.1) | 4.4 (8.9)** | 1.4 (3.5) | 6.47a | 2,83 | .002 |
| Last consumption (days)j | 121.6 (5.1);n = 1 | 73.6 (3.1);n = 10 | 90.9 (3.8);n = 3 | .29a | 2,11 | .75 | 17.5 (0.7);n = 1 | 35.7 (1.5);n = 8 | 99.8 (4.2);n = 4 | 1.48a | 2,10 | .27 |
| Hair analysis (ng/mg) | 0.0 (0.0) | 0.1 (0.2)* | 0.0 (0.0) | 4.35a | 2,83 | .02 | 0.0 (0.0) | 0.1 (0.2) | 0.1 (0.2) | 2.89a | 2,83 | .06 |
| MDMA n | ||||||||||||
| Tablets per weekh | 0.0 (0.0) | 0.0 (0.1)*** | 0.0 (0.0)° | 7.42a | 2,83 | .001 | 0.0 (0.0) | 0.4 (0.9)** | 0.0 (0.0)° | 5.54a | 2,83 | .006 |
| Years of use | 0.3 (1.0) | 3.5 (4.5)*** | 2.4 (4.6)* | 8.42a | 2,83 | <.001 | 0.2 (1.4) | 3.8 (5.5)** | 3.2 (5.6)* | 7.78a | 2,83 | <.001 |
| Cumulative dose (tablets) | 1.3 (4.0) | 108.8 (249.7)** | 18.7 (46.2) | 5.71a | 2,83 | .005 | 0.2 (0.8) | 17.0 (49.3)* | 2.8 (5.2) | 3.67a | 2,83 | .03 |
| Last consumption (days)j | 5.0 (0.2);n = 1 | 89.9 (3.7);n = 7 | 40.2 (1.7);n = 4 | 1.63a | 2,9 | .25 | 91.2 (3.8);n = 3 | 41.6 (1.7);n = 6 | 47.8 (2.0);n = 5 | 1.11a | 2,11 | .36 |
| Hair analysis (ng/mg) | 0.0 (0.0) | 0.3 (0.7) | 0.4 (1.5) | 2.23a | 2,83 | .11 | 0.0 (0.0) | 0.5 (0.8)*** | 0.1 (0.3) | 7.87a | 2,83 | <.001 |
| GHB n | ||||||||||||
| Cumulative dose (pipettes) | 0.0 (0.0) | 0.5 (0.7) | 0.5 (1.7) | 3.36a | 2,83 | .04 | 0.0 (0.0) | 0.0 (0.0) | 0.0 (0.0) | – | – | – |
| Hallucinogens n | ||||||||||||
| Cumulative dose (times) | 0.9 (2.2) | 27.9 (72.8)* | 9.9 (22.9) | 3.92a | 2,83 | .02 | 0.0 (0.0) | 1.1 (1.6)*** | 0.6 (1.5) | 8.57a | 2,83 | <.001 |
| Methlyphenidate n | ||||||||||||
| Cumulative dose (tablets) | 0.0 (0.0) | 20.2 (60.4)* | 0.5 (2.3) | 3.76a | 2,83 | .03 | 0.0 (0.1) | 67.7 (239.5) | 0.3 (0.6) | 2.72a | 2,83 | .07 |
| Hair analysis (ng/mg) | 0.0 (0.0) | 0.0 (0.1) | 0.0 (0.0) | 1.80a | 2,83 | .17 | 0.0 (0.0) | 0.1 (0.2)* | 0.0 (0.0) | 3.62a | 2,83 | .03 |
Means and standard deviations. Significant p values are shown in bold.
ANOVA (all groups, with significant Sidak post hoc test vs. control group: *p < .05; **p < .01; ***p < .001; vs. cocaine increaser: p < .05).
χ²-test (all groups/cocaine users only) for frequency data.
Independent t-test (cocaine users only).
Verbal IQ was assessed by the Mehrfachwahl Wortschatz Intelligenztest (46).
ADHD-SR, ADHD self-rating scale (cutoff DSM-IV criteria) (33).
Smoking habits were assessed by the Fagerstroem Test of Nicotine Dependence (47).
BDI, Beck Depression Inventory (cutoff ≥ 18) (48).
Average use during the last 6 months.
Craving for cocaine was assessed by the Brief-CCQ (49).
Last consumption is averaged only for persons who used the drug in the last 6 months.
Urine toxicology (neg/pos) are based on the cutoff value for cocaine = 150 ng/ml and for tetrahydrocannabinol 50 ng/ml (50). The χ²-test for cocaine includes only cocaine users; the χ²-test for cannabis includes controls and cocaine users.
Hair samples were voluntary and data are missing for three controls.
Parameters at follow-up refer to the 1-year period between t1 and t2.
At baseline, average use during the last 6 months. Use frequency, duration of use, and cumulative doses are averaged within the total group.