Salivary cortisol and alpha‐amylase daily profiles and stress responses to an academic performance test and a moral cognition task in children with neurodevelopmental disorders

Abstract

There is evidence that children with neurodevelopmental disorders may exhibit atypical responses to stress and alterations in concentrations and diurnal secretion of stress hormones. We assessed diurnal profiles and stress responses of salivary cortisol and alpha‐amylase (sAA) in children with attention‐deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD) and specific learning disorder (SLD) compared to typically developing children (TD). A total of 157 children of both sexes, aged between 6 and 12 years old, took part in the study distributed into four groups: ADHD (N = 34), ASD (N = 56), SLD (N = 43) and TD (N = 24). Salivary samples were collected at three time points during a day, as well as before and 5 min after an academic performance test and a moral cognition task. ADHD children had lower evening and diurnal sAA levels, adjusted for age. Also, ASD children showed lower diurnal sAA secretion, adjusted for age. The mean percentage change for salivary cortisol and sAA after both tests did not differ between the groups. In conclusion, we demonstrated alterations in diurnal autonomic functioning in children with ADHD and ASD, while hypothalamic–pituitary–adrenal axis functioning did not differ between the clinical and the comparison groups.

Cortisol and inflammatory biomarker levels in youths with attention deficit hyperactivity disorder (ADHD): evidence from a systematic review with meta-analysis

“…However, these factors are often less mentioned in most of the studies. We have carried out a qualitative examination on the aforementioned factors in the included studies of our meta-analysis (see Table 1 and Supplementary Table S3 ) and found that although most of the studies [ 3 – 5 , 20 , 22 – 26 , 29 – 34 , 36 , 37 ] reported ADHD medication use status except for Jansen et al [ 28 ] and Ma et al [ 35 ], none mentioned about the 21-hydroxylase genetic mutations. In addition, although most of the included studies, other than those collected awakening salivary cortisol levels [ 3 , 20 , 22 , 23 , 26 , 32 ], did not report the resting time required prior to the sample collection, however, they did ask the patients to have at least 30 min to a 90 min gap between brushing their teeth, eating/ drinking and the sample collection; [ 4 , 5 , 20 , 24 , 25 , 31 , 34 – 37 ] and at least a 90 min to a 24 h restriction of strenuous exercises prior to the sample collection [ 5 , 20 , 25 , 35 ].…”

“…We have carried out a qualitative examination on the aforementioned factors in the included studies of our meta-analysis (see Table 1 and Supplementary Table S3 ) and found that although most of the studies [ 3 – 5 , 20 , 22 – 26 , 29 – 34 , 36 , 37 ] reported ADHD medication use status except for Jansen et al [ 28 ] and Ma et al [ 35 ], none mentioned about the 21-hydroxylase genetic mutations. In addition, although most of the included studies, other than those collected awakening salivary cortisol levels [ 3 , 20 , 22 , 23 , 26 , 32 ], did not report the resting time required prior to the sample collection, however, they did ask the patients to have at least 30 min to a 90 min gap between brushing their teeth, eating/ drinking and the sample collection; [ 4 , 5 , 20 , 24 , 25 , 31 , 34 – 37 ] and at least a 90 min to a 24 h restriction of strenuous exercises prior to the sample collection [ 5 , 20 , 25 , 35 ]. What is more striking is that only 3 studies [ 5 , 20 , 25 ] asked their participants not to drink alcohol or smoke prior to the sample collection or mentioned substance use disorder in the exclusion criteria, although about more than half the studies [ 3 , 20 , 24 , 25 , 30 – 32 , 34 , 35 , 37 ] included in the meta-analysis enrolled teenagers with age ≥13, a population relatively at risk for substance use.…”

“…Our criteria were: the studies (1) measured levels of cortisol of blood or salivary sample; (2) participants were school-aged children (4–12 years) and adolescents (13–17 years) who had a diagnosis of ADHD; (3) the data allowed to calculate an effect size; and (4) the publications were in peer-reviewed journals. Nineteen studies [ 3 – 5 , 20 , 22 – 26 , 28 – 37 ] were included in the meta-analysis on cortisol levels.…”

“…In this study, we have updated the previously published meta-analysis [ 7 ] of cortisol levels by including seven recent studies [ 3 , 20 , 22 – 26 ]. Noteworthy, we assessed also the time of sample collection in potentially explaining the variability in the findings, not considered by the previous meta-analysis [ 7 ].…”

Stress/Immune Biomarkers in Saliva among Children with ADHD Status

“…In one ADHD study, a lower evening and diurnal sAA secretions in response to stress were noted [ 54 ]. It should be remembered that the salivary glands are innervated by both the sympathetic and parasympathetic parts of the autonomic nervous system (ANS).…”