Risk factors for the existence of attention deficit hyperactivity disorder symptoms in children with autism spectrum disorders

Figures & data

Table 1 Univariate correlation of coexisting somatic or neuropsychiatric problems with CPRS-R DSM-IV ADHD scores in children with ASD

Coexisting somatic or neuropsychiatric problems	N (%)	Mean	P-value
Gender (male)	57 (85%)	0.124	0.174
Age (mean ± SD)	88.12±44.1	0.207	0.048*
IQ (mean ± SD)	66.9±37.1	−59	0.33
Macrocephaly	7 (10%)	−0.141	0.144
Obesity (BMI >95th percentile)	19 (28%)	−0.141	0.195
Motor delay	19 (28%)	0.231	0.039*
Speech delay	59 (88%)	−0.177	0.189
Enuresis	22 (32%)	0.285	0.014*
Minor neurological signs	37 (52%)	0.053	0.353
EEG abnormalities	12 (18%)	0.064	0.315
Allergies	20 (30%)	0.474	0.0001*
Neuropsychiatric comorbidities
Tic disorders	7 (10%)	−0.015	0.454
ODD	1 (1.5%)	0.255	0.026*
Intellectual disabilities	15 (22%)	0.24	0.034*
Anxiety disorders	1 (1.5%)	0.162	0.11
Sleep disorders	1 (1.5%)	−0.075	0.287
Mood disorders	1 (1.5%)	0.145	0.136

Note:

* P<0.05.

Abbreviations: CPRS-R, Conner’s Parent Rating Scale-Revised; DSM-IV, Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition; ADHD, attention deficit hyperactivity disorder; ASD, autism spectrum disorder; IQ, intelligent quotient; BMI, body mass index; EEG, electroencephalogram; ODD, comorbid oppositional defiant disorder; SD, standard deviation.

Table 2 Univariate correlation of familiar predictors with CPRS-R DSM-IV ADHD scores in children with ASD

Familiar predictors	N (%)	Mean	P-value
Neurological familiality
Migraine	9 (13%)	202	0.062
Epilepsy	17 (25%)	−0.06	0.327
Cerebral palsy	4 (6%)	−0.171	0.097
Psychiatric familiality
Intellectual disabilities	12 (18%)	0.355	0.003*
Specific learning disorders	3 (4%)	−0.088	0.253
Tic disorders	6 (9%)	0.083	0.266
Psychosis	12 (18%)	0.231	0.039*
Anxiety disorders	12 (18%)	0.165	0.106
Depression	12 (18%)	0.075	0.285
Substance abuse	1 (1.5%)	0.162	0.11
Autism spectrum disorders	3 (4.5%)	0.022	0.434
ADHD	2 (3%)	0.189	0.076
Mother’s age (mean ± SD)	38.5±5.9	−0.106	0.213
Father’s age (mean ± SD)	41.8±6.6	−0.104	0.216
Psychosocial risk factorsa	16 (30%)	−0.031	0.408

Notes:

* P<0.05.

a Abnormal intrafamilial relationship patterns and dysfunctional parenting (absence of a parent, quarrels, parental separation/divorce, excessive severity, excessive worries, special predilections), deaths in the family, hospitalizations, psychiatric disorder or disability in parent or sibling, institutional education outside the family, migration, frequent removals, frequent changes of school classes, discrimination and adverse school circumstances (ie, bullying), severe financial difficulties, belonging to a group of disadvantage, very inadequate home and not fluent in the local language.

Abbreviations: CPRS-R, Conner’s Parent Rating Scale-Revised; DSM-IV, Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition; ADHD, attention deficit hyperactivity disorder; ASD, autism spectrum disorder; SD, standard deviation.

Table 3 Univariate correlation of pregnancy risk factors with CPRS-R DSM-IV ADHD scores in children with ASD

Pregnancy risk factors	N (%)	F value, rp	P-value
Recurrent abortions	9 (13%)	−0.072	0.293
Threatened miscarriage	10 (15%)	0.078	0.28
Maternal smoking	8 (11.9%)	0.173	0.095
Infections	1 (1.5%)	0.164	0.95
Preeclampsia	3 (4.5%)	0.191	0.073
Medications during pregnancy	4 (6%)	−0.127	0.17
Placental abruption	1 (1.5%)	0.12	0.183
Gestational diabetes	2 (3%)	−0.082	0.267
Intrauterine growth retardation	1 (1.5%)	0.179	0.087
Peripartum risk factors			0.489
Premature birth	8 (12%)	0.189	0.18
Low birth weight	10 (15%)	0.202	0.062
Difficult delivery	7 (10%)	0.231	0.342
Perinatal cyanosis	3 (4.5%)	0.056	0.336
Postpartum risk factors
Early infections	4 (6%)	0.016	0.452
Respiratory distress	1 (1.5%)	−0.004	0.488
Neonatal cardiac rhythm disturbances	2 (3%)	0.08	0.272

Note: No statistically significant difference was found.

Abbreviations: CPRS-R, Conner’s Parent Rating Scale-Revised; DSM-IV, Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition; ADHD, attention deficit hyperactivity disorder; ASD, autism spectrum disorder.

Table 4 Factors associated with increased DSM-IV ADHD scores in children with ASD

Factors associated	t	β	CI95% for β	P-value
Age	1.66	0.23	−0.16 to 0.16	0.1
Motor delay	1.57	0.17	−13.8 to 1.66	0.12
Intellectual disabilities	0.72	0.14	−12.8 to 13.66	0.91
Enuresis	1.77	0.3	−0.7 to 11.4	0.83
ODD	0.29	1.62	−9.04 to 12.64	0.76
NPF for intellectual disabilities	0.19	1.53	−2.5 to 18.4	0.13
Allergies	3.84	0.39	6.31–21.03	0.001*
NPF for psychosis	2.22	0.22	2.01–23.6	0.03*

Notes: Model with two predictors (allergies and NPF for psychosis): R²=0.28 (corrected R²=0.25).

* P<0.05.

Abbreviations: DSM-IV, Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition; ADHD, attention deficit hyperactivity disorder; ASD, autism spectrum disorder; ODD, comorbid oppositional defiant disorder; NPF, neuropsychiatric familiality.