Table 1.
A Comparison of characteristics of patients and controls
| Controls (n=20) | Patients (n=20) | test statistic | p-value | |
|---|---|---|---|---|
| Demographics: | ||||
| Age (mean(sd)) | 16.5 (1.6) | 16.5 (1.0) | t=0.003 | 0.99 |
| Race: | ||||
| Caucasian (n) | 15 | 12 | χ2 =1.03 | 0.31 |
| Non-Caucasian (n) | 5 | 8 | ||
| Education: | ||||
| Highest-grade comp. (mean(sd)) | 9.70 (1.69) | 9.15 (0.98) | M-W-U=158.5 | 0.25 |
| Ever repeated grade (n) | 1 | 6 | Fisher's Exact | 0.09 |
| Clinical Measures: | ||||
| IQ full-scale (sd) | 104.9 (9.0) | 97.3 (8.9) | t=2.67 | 0.01 |
| Carroll Rating Scale (sd) | 4.1 (3.8) | 8.5 (6.7) | M-W-U=106.5 | 0.01 |
| Attention Deficit Hyperactivity Problems t-scoreB | 53.5 (4.5) | 58.3 (8.2) | t=2.28 | 0.002 |
| Impulsivity, Aggression and Conduct Disorder: | ||||
| Eysenck Impulsivity Scale (sd) | 6.7 (4.5) | 11.9 (6.0) | t=6.84 | 0.004 |
| Aggression score | 0.5 (1.1) | 5.7 (3.2) | M-W-U=40.5 | <0.001 |
| Lifetime CD diagnosis (n) | 1 | 19 | χ2 =36.1 | <0.001 |
| Substance Use Disorders (SUD): | ||||
| SUD Symptoms Across Drugs (sd) | 0.2 (0.67) | 12.4 (7.2) | M-W-U=2.0 | <0.001 |
| Alcohol Abuse | 0 | 8 | Fisher's Exact | <0.004 |
| Alcohol Dependence | 8 | Fisher's Exact | <0.004 | |
| Amphetamine Dependence | 0 | 2 | Fisher's Exact | NS |
| Cannabis Abuse | 0 | 7 | Fisher's Exact | <0.009 |
| Cannabis Dependence | 0 | 10 | χ2 =13.33 | 0.0003 |
| Club Drugs Abuse | 0 | 3 | Fisher's Exact | NS |
| Club Drugs Dependence | 0 | 4 | Fisher's Exact | NS |
| Cocaine Abuse | 0 | 2 | Fisher's Exact | NS |
| Cocaine Dependence | 0 | 2 | Fisher's Exact | NS |
| Hallucinogen Abuse | 0 | 2 | Fisher's Exact | NS |
| Hallucinogen Dependence | 0 | 1 | Fisher's Exact | NS |
| Tobacco Dependence | 1 | 13 | χ2 =15.82 | <0.0001 |
Groups were compared based on appropriate statistical tests based on normality.
For attention deficit hyperactivity problem t-score missing Child Behavioral CheckList (Achenbach, 1991a) score for one patient was replaced by Youth Self Report score (Achenbach, 1991b)
IQ reported in Crowley et al. (2010) has two typos that have been addressed in this manuscript i) Patient IQ Instead of 97.1(9.3) is 97.3(8.9) and ii) the IQ full-scale t-score is IQ full-scale
Abbreviations:
sd=standard deviation; IQ=intelligence quotient measured by the two subtests from the Wechsler Abbreviated Scale of Intelligence;
Carroll Rating Scale score of >=10 is suggestive of clinical depression;
CD diagnosis=at least three lifetime DSM-IV conduct disorder symptoms; n=count (total number); sd=Standard Deviation; SUD=Substance Use Disorder;
t=t-value for the t-test;
χ2= Chi-square test (without the Yates continuity correction);
M-W-U=Mann-Whitney-U