Gray matter covariations and core symptoms of autism: the EU-AIMS Longitudinal European Autism Project

Table 1 Participant characteristics

Demographic	Autism, n = 347		TD, n = 252		t/χ²	p value
Demographic	Mean	SD	Mean	SD	t/χ²	p value
Age, years^a	16.79	5.56	16.92	5.71	− 0.270	0.788
FSIQ^a,b	99.40	18.94	104.88	18.26	− 3.549	p < 0.001
FSIQ ≥ 75	104.29	14.95	109.02	13.07	− 3.883	p < 0.001
FSIQ < 75	66.61	5.44	63.69	9.20	1.399	0.172

	n	%	n	%
Sex, male/female^c	253/94	72.9/27.1	163/89	64.7/35.3	4.658	0.031
ADHD rating scale^d, with/without ADHD	139/160	46.5/53.5	21/180	10.4/89.6	71.750	p < 0.001

TD, typically developing; SD, standard deviation; FSIQ, full-scale intelligence quotient; ADHD, Attention Deficit Hyperactivity Disorder; ADI, Autism Diagnostic Interview-Revised; RRB, restricted, repetitive behaviors; ADOS, Autism Diagnostic Observational Schedule 2; SRS, Social Responsiveness Scale 2nd Edition; RBS, Repetitive Behavior Scale-Revised; SSP, Short Sensory Profile
^aStatistical differences were assessed by two-sample t test
^bIn Schedule A, B, and C (FSIQ ≥ 75), there are 302 participants with autism and 229 participants with TD. Schedule D (FSIQ < 75) comprised 45 participants with autism and 23 TD individuals
^cSex difference was examined by the chi-square test
^dADHD rating scores were available for 500 participants, including 299 individuals with autism and 201 TD individuals
^eADI scores were available for 332 participants
^fADOS scores were available for 339 participants. We considered calibrated severity scores
^gParent report SRS scores were available for 284 participants with autism and 135 TD individuals
^hRBS scores were available for 277 participants with autism and 133 TD individuals
ⁱSSP scores were available for 201 participants with autism and 115 TD individuals
^g,h,iIn all questionnaires, the scores of the autism group only were used in our study, and they are all parent-rated

ISSN: 2040-2392