Table 1. Demographic and Clinical Characteristics of Healthy Control Individuals and Participants With Conduct Problemsa.
| Participant Characteristic | Healthy Controls (n = 16) | Conduct Problems (n = 30) | P Value | Low CU (n = 16) | High CU (n = 14) | P Value |
|---|---|---|---|---|---|---|
| Demographic variable, mean (SD) | ||||||
| Male:female ratio | 10:6 | 16:14 | .76 | 9:7 | 7:7 | >.99 |
| Age, y | 12.75 (2.41) | 14.74 (2.46) | .01b | 14.09 (2.69) | 15.50 (2.00) | .12 |
| Cognitive intelligence score | 112.69 (15.38) | 98.10 (9.73) | <.001b | 100.56 (10.94) | 95.29 (7.54) | .14 |
| Behavioral measure, mean (SD) | ||||||
| CBCL/DSM scalec | 43.38 (9.47) | 72.70 (4.94) | <.001b | 71.50 (5.11) | 74.07 (1.30) | .16 |
| Affective | 0.81 (1.33) | 6.93 (4.93) | <.001b | 7.19 (5.44) | 6.64 (4.47) | .77 |
| Clinical threshold, No. | 0 | 13 | .002b | 8 | 5 | .48 |
| Anxiety | 0.94 (1.34) | 3.23 (3.07) | .01b | 3.56 (3.16) | 2.93 (3.05) | .58 |
| Clinical threshold, No. | 0 | 8 | .04b | 5 | 3 | .69 |
| ADHD | 1.06 (1.29) | 8.13 (3.42) | <.001b | 7.81 (3.43) | 8.50 (3.50) | .59 |
| Clinical threshold, No. | 0 | 10 | .01b | 3 | 7 | .12 |
| Alcohol use, No.d | 0 | 3 | .54 | 1 | 2 | .59 |
| Drug use, No.d | 0 | 5 | .15 | 2 | 3 | .64 |
| ICUe | 25.50 (6.66) | 44.28 (8.31) | <.001b | 38.13 (5.35) | 51.32 (4.58) | <.001b |
| Reactive aggressionf | 6.12 (4.29) | 12.47 (4.46) | <.001b | 12.56 (4.230) | 12.36 (4.58) | .90 |
| Proactive aggressionf | 0.88 (1.09) | 6.40 (5.54) | <.001b | 5.44 (4.70) | 7.50 (6.19) | .31 |
| fMRI task accuracy, % | 92.79 (6.69) | 93.21 (4.99) | .81 | 91.91 (5.98) | 94.67 (3.15) | .14 |
| fMRI task reaction time, ms | 914.92 (116.05) | 900.12 (132.53) | .71 | 920.49 (138.36) | 876.85 (126.49) | .38 |
Abbreviations: ADHD, attention-deficit/hyperactivity disorder; CBCL, Child Behavior Checklist; CU, callous-unemotional; fMRI, functional magnetic resonance imaging; ICU, Inventory of Callous-Unemotional Traits.
Cognitive intelligence is the full-scale IQ from the Kaufman Brief Intelligence Test–2.
Significant group differences at P < .05, 2-tailed, measured with t tests except for Fisher exact test for categorical variables.
CBCL scores are the age- and sex-standardized t scores of externalizing behavior (items measuring aggression and rule breaking). CBCL/DSM scores are from the CBCL/DSM-oriented scales and the number of participants who meet the age- and sex-normed cutoffs that indicate symptoms in the clinical range are given below each scale.
Drug and alcohol use are derived from parent reports indicating frequent use.
ICU scores are derived from the maximum score on each item from the parent and youth versions.
Reactive and proactive aggression are subscores from the Reactive-Proactive Aggression Questionnaire.