Table 2.

Studies Examining Cortisol Responsiveness in Autism Spectrum Disorder Cohorts

Authors	ASD sample	Comparison sample	Methods	Summary of findings	Notes
Basic Regulatory Processes
*Hamza et al, 2010	50 participants with autistic disorder. Age range = 3 to 12 years.	age-, sex-, and pubertal-stage matched TD controls (not matched on IQ)	Plasma cortisol response to ACTH-S	Lower cortisol values in ASD group than controls 60 minutes after ACTH-S Cortisol response to ACTH-S in ASD group depended on level of functioning	Lower basal cortisol levels in ASD group and those who had more severe autism not accounted for.
Hoshino et al., 1984	19 participants with autistic disorder. Age range=5 to 20 years (M = 11.5 years).	4 comparison groups (TD adults, adults with schizophrenia, children with intellectual disability, children with attention deficit disorder)	plasma cortisol response to DST	Suppression depended on level of functioning of participants	Significant age range spanning pubertal stages
*Hoshino et al, 1987	22 participants with autistic disorder. Mean age = 9 years (range not given).	TD children and TD adults (not matched on IQ)	plasma and salivary cortisol response to DST	Suppression depended on level of functioning of participants
Jensen et al., 1985	13 participants with autistic disorder. Age range = 2 to 17 years.	None	plasma cortisol response to DST	85% of participants did not show suppression	All but 1 participant had IQ of 40 or less. Large age range
*Marinovic- Curin et al., 2008	9 participants with autistic disorder. Mean age = 11.9 years (range not given).	age-matched, TD controls (not matched on IQ) for DST. TD adults for ACTH-S.	salivary cortisol response to DST and ACTH-S	No group differences in cortisol values after DST Lower cortisol values in the ASD group 90 minutes after ACTH-S Differences between groups were non-significant at 120 minutes	Level of functioning of sample not provided. Comparison sample for ACTH-S was adults.
Non-Social Environmental Stressors
*Corbett et al., 2006	12 participants with autistic disorder. Age range = 6 to 11 years (M = 8.5 years).	TD children, matched on age and gender (not matched on IQ)	salivary cortisol response to mock MRI	Children with ASD showed elevated cortisol in response to stressor relative to controls
*Corbett et al., 2008	22 participants with autistic disorder. Age range = 6.5 to 12 years (M = 8.8 years).	TD children, matched on age (not matched on IQ)	salivary cortisol response to mock MRI	Children with ASD did not show elevated cortisol in response to stressor ASD and TD groups showed elevated cortisol before second exposure to stressor (anticipatory stress) No significant relations between IQ and cortisol	Children were excluded if IQ scores were less than 80. Children with ASD were slightly higher functioning than in their 2006 sample
*Corbett et al., 2009	22 participants with autistic disorder. Age range = 6 to 12 years (M = 8.8 years).	TD children, matched on age (not matched on IQ)	salivary cortisol response to mock MRI	Children with ASD and TD groups did not show cortisol response to stressor Diagnoses (ASD vs. TD) did not differentiate responders from non- responders. Nor did behavioral stress, sensory functioning, or parenting stress.	Children were excluded if IQ scores were less than 80.
Jansen et al., 1999	12 participants with PDD-NOS. Age range = 6 to 12 years.	4 comparison groups (children with dysthymia, oppositional defiant disorder/conduct disorder, attention deficit hyperactivity disorder, or no psychiatric diagnoses)	salivary cortisol response to attention task and physical stressor (bike ride)	Attention task did not result in rise in cortisol for ASD or any of the comparison groups ASD and dysthymia groups had lower cortisol responses to physical stressor (smaller area under the curve) than TD controls	Level of functioning of sample not provided.
*Jansen et al., 2003	10 participants with PDD-NOS (all with MCDD) and 10 with autistic disorder. Mean age = 9.4 years (range not given).	TD children, matched on age (no information about IQ in comparison group)	salivary cortisol response to physical stressor (bike ride)	Cortisol values rose for all groups after the physical stressor There were no differences in cortisol response by diagnostic group	Children with intellectual disability were excluded.
Spratt et al., 2012	20 participants with autistic disorder. Age range = 3 to 10 years (M = 7.0 years)	TD children who were younger on average	salivary cortisol response to blood draw	Both groups had elevated cortisol in response to blood draw ASD group had a higher peak in cortisol and elevated cortisol lasted longer after blood draw than the comparison group Area under the curve in response to blood draw was greater for ASD group Cortisol values were not correlated with autism symptoms	Children with IQ scores less than 55 were excluded. No other information on level of cognitive functioning.
Psychosocial Stressors
Corbett et al., 2010	21 participants with autistic disorder. Age range = 8 to 12 years (M = 10.0 years)	TD children, matched on age (not matched on IQ)	salivary cortisol response to playground interaction	On average, no cortisol response to stressor for control group In ASD group, older children showed cortisol response to stressor; younger children did not. Autism severity did not predict cortisol response	Children with IQ scores less than 75 were excluded.
Corbett et al., 2012	27 participants with autistic disorder (n = 22) or PDD-NOS (n = 5) Age range = 8 to 12 years (M = 10.1 years)	TD children matched on age (not matched on IQ)	salivary cortisol response to TSST and playground interaction	TSST did not elicit a cortisol response from ASD group, but did elicit a response from the control group. ASD group had prolonged cortisol reaction to playground interaction, but control group did not ASD group had greater variability than control group Age (but not IQ) was related to higher cortisol response to playground interaction in ASD group	Analyses examining responses to both playground and TSST included 14 children with ASD and 8 controls. Children with IQ scores less than 75 were excluded.
Jansen et al., 2000	10 participants with PDD-NOS (all with MCDD), Mean age = 9.8 years. (range not given)	TD children matched on age (no information about IQ in comparison group)	salivary cortisol response to TSST-like task	Stressor resulted in significant increase in cortisol for controls, but not for ASD group. Difference in cortisol response between control and ASD group was statistically significant Antipsychotic medication use was not related to cortisol response	IQ range of ASD group was 69–110. 6 participants in ASD group were on antipsychotic medications
*Jansen et al., 2003	10 participants with PDD-NOS (all with MCDD), Mean age = 9.9 years. 10 participants with autistic disorder, Mean age =9.4 years. (ranges not given).	TD children, matched on age (no information about IQ in comparison group)	salivary cortisol response to TSST-like task	Children with PDD-NOS had less cortisol response to the stressor than controls. Children with autistic disorder did not differ from controls in response to stressor (both experienced a stress response on average) Children with autistic disorder had higher cortisol than controls during the control test More communication impairments in the ASD group were related to greater cortisol response to stressor. IQ was not related to cortisol response.	Children with intellectual disability were excluded.
Jansen et al., 2006	7 participants with autistic disorder and 3 with Asperger syndrome, Mean age = 21.8 years (range not given)	TD adults, matched on age and IQ	salivary cortisol response to TSST-like task	Both ASD and control groups showed cortisol response to stressor No significant differences in cortisol response between ASD and control groups	Adults with IQ scores less than 70 were excluded
Lanni et al., 2012	15 participants with autistic disorder Age range = 8 to 12 years (M = 9.9 years)	TD children matched on age (not matched on IQ)	salivary cortisol response to TSST	Cortisol response to stressor did not significantly differ between groups However, a one-sample t-test showed a significant response for controls, but not for the children with ASD Verbal ability did not predict cortisol response to the TSST	Children with IQ scores less than 70 were excluded.
Levine et al., 2012	8 participants with PDD-NOS, 9 with Asperger’s disorder, and 2 with autistic disorder (total n = 19) Age range = 8 to 12 years (M = 9.7 years)	TD children matched on age. IQ was higher in comparison group but not significantly so.	salivary cortisol response to TSST	No significant differences between groups in any of the cortisol samples ASD group did not have cortisol response to stressor Comparison group had greater change in cortisol in response to stressor than ASD group	Some children in the control group were siblings of the children with ASD. Children with IQ scores less than 70 were excluded.
Lopata et al., 2008	33 children with ASD. Age range = 6 to 13 years (M = 9.8 years)	No control group (within-subjects design)	salivary cortisol response to familiar vs. unfamiliar peer	Those who played with a familiar peer first had lower cortisol when exposed to the familiar peer, and higher cortisol when exposed to the unfamiliar peer Children who played with the unfamiliar peer first had similar cortisol levels when exposed second to the familiar peer Children had a greater stress response to the unfamiliar peer after they had played with the familiar peer. Moderate relations between self- reported stress and cortisol	Children with IQ scores less than 70 were excluded.
Naber et al., 2007	20 children with autistic disorder and 14 children with PDD-NOS. Mean age = 29.8 months	12 children with intellectual disability, 16 children with language disorder, 18 TD children. Control groups of similar age	salivary cortisol response to Strange Situation	Children with autistic disorder had greater cortisol response to caregiver separation (stressor) relative to TD control group More autistic symptoms predicted less cortisol response to stressor.
Schupp et al., 2013	21 children with autistic disorder and 5 children with PDD-NOS. Age range = 8 to 12 years (M = 10.2 years)	TD children, matched on age and gender (not matched on IQ)	salivary cortisol response to playground interaction	38.5% of children with ASD had a cortisol response to the stressor, compared to 19.2% of the control group In ASD group, older children showed greater cortisol response to stressor relative to younger children

Note. Studies marked with an asterisk appear more than once in Table 1 and/or 2. ACTH-S = ACTH Stimulation Test; DST = Dexamethasone Suppression Test; TD = typically developing; ASD = autism spectrum disorder; PDD-NOS = Pervasive Developmental Disorder – Not Otherwise Specified; MCDD = Multiple Complex Developmental Disorder; TSST = Trier Social Stress Test