Cardiac reactivity and stimulant use in adolescents with autism spectrum disorders with comorbid ADHD versus ADHD.
Heart-rate reactivity does not separate ASD+ADHD teens from ADHD-only teens, and stimulants speed reaction time while dampening heart-rate flexibility in both groups.
01Research in Context
What this study did
The team compared 25 teens who have both autism and ADHD with 25 teens who have only ADHD.
All kids were 11-17 years old and already taking stimulant medicine.
While the teens did a simple reaction-time game, the researchers tracked heart-rate patterns.
They wanted to know if the two groups looked different on heart measures and if the medicine changed those measures.
What they found
Heart-rate reactivity was the same in both groups.
Stimulant medicine sped up reaction times and reduced low-frequency/high-frequency heart-rate balance in both groups.
In plain words, the drug made them faster and blunted their natural heart-rate flexibility, but it did so equally for both diagnoses.
How this fits with other research
van den Broek et al. (2006) saw blunted heart-rate reactivity in autistic adults facing public speaking.
The new teen data seem opposite, but age and added ADHD explain the gap: kids with both diagnoses show typical teen heart patterns, not the adult blunting.
Rutter et al. (1987) first found odd catecholamine storage in autistic children.
The 2015 study extends that old biochemistry work by showing stimulants still tweak the autonomic system in today’s ASD+ADHD teens.
Rasing et al. (1992) showed teacher reprimands can match stimulants for ADHD behavior.
Here, we learn the drug’s body effects are the same whether or not autism is present, keeping behavior tools like reprimands on the table.
Why it matters
You can’t use heart-rate tests to tell ASD+ADHD from plain ADHD in teens.
If you’re starting stimulants, expect faster responding and less heart-rate flexibility in both groups, so monitor sleep and appetite, not cardiac diagnosis.
Because the drug works the same, lean on behavior plans, self-monitoring, and parent reports just as you would with any ADHD client.
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02At a glance
03Original abstract
A large number of youngsters with autism spectrum disorders (ASD) display comorbid attention deficit/hyperactivity disorder (ADHD) symptoms. However, previous studies are not conclusive whether psychophysiological correlates, like cardiac reactivity, are different for ASD with comorbid ADHD (ASD+) compared to ADHD. Therefore, the current study investigated (dis)similarities in cardiac reactivity and attention task performance. In a clinical sample, adolescents diagnosed with ASD+ (n = 20) versus ADHD (n = 36) and stimulant medication use (56 %) were compared during a baseline with eyes closed and task performance. Results for cardiac reactivity were similar for both diagnostic groups. Stimulant-medicated adolescents showed decreased adaptation of LF/HF ratio and faster reaction times than stimulant-free adolescents. The current study underlines the psychophysiological overlap of ADHD symptoms in adolescents with ASD+ and adolescents with ADHD.
Journal of autism and developmental disorders, 2015 · doi:10.1007/s10803-013-1929-1