Table 1.

Sample characteristics

Characteristic	Cases (n = 118)	HC (n = 89)	Test statistic	p
Age (years)	13.23 ± 2.68	13.40 ± 2.49	t(205) = − 0.45	0.65
Sex, m/f	99/19	51/38	χ2 = 17.98	< 0.001
IQa	100.78 ± 11.00	106.64 ± 10.42	t(195) = − 3.81	< 0.001
Handedness, left/right	16/95	10/77	χ2 = 0.37	0.55
CD plus ODD diagnosisb	25
ODD diagnosisb	48
CD diagnosisb	7
ADHD diagnosisb	29
CBCL—Aggression T-score	74.46 ± 10.10	51.77 ± 6.19	t(197) = − 12.78	< 0.001
CBCL—Rule-breaking T-score	69.00 ± 12.14	51.69 ± 6.72	t(196) = − 20.54	< 0.001
K-SADS—inattention	3.33 ± 2.91
K-SADS—hyperactivity	1.66 ± 1.91
K-SADS—impulsivity	1.08 ± 1.20
ICU—total score	33.68 ± 10.16	21.00 ± 8.70	t(196) = − 9.44	< 0.001
ICU—callousness	12.00 ± 6.11	4.00 ± 3.44	U = 2278.00	< 0.001
ICU—uncaring	17.00 ± 3.93	10.41 ± 5.07	U = 2445.00	< 0.001
ICU—unemotional	7.17 ± 3.31	5.22 ± 2.75	t(189) = − 4.37	< 0.001
RPQ—reactive aggression	12.55 ± 5.09	5.00 ± 3.48	U = 1296.50	< 0.001
RPQ—proactive aggression	3.00 ± 5.01	0.82 ± 1.45	U = 1807.50	< 0.001
Medication usec	70
Stimulants	52
Neuroleptics	18
Antidepressants	2
Mean RMS-FD	0.12 ± 0.17	0.09 ± 0.18	U = 4134.50	< 0.01

Values are means or, for non-normal distributions, medians ± SD or counts

ADHD attention-deficit hyperactivity disorder, CBCL Child Behavior Checklist, CD conduct disorder, HC healthy controls, ICU inventory of callous-unemotional traits, parent report, K-SADS Kiddie Schedule for Affective Disorders and Schizophrenia, ODD oppositional defiant disorder, RMS-FD root mean square framewise displacement, RPQ Reactive and Proactive aggression Questionnaire

^aIQ estimated based on four sub-tests derived from the Wechsler Intelligence Scale for Children IV

^bDiagnoses derived from the Kiddie Schedule for Affective Disorders and Schizophrenia Present and Lifetime version

^cMedication use according to parental or clinical reports