The 3 As: Autism, ADHD and Age

Posted on October 10, 2018

This study carries implications for clinical practice – if an adult client is undergoing treatment for one of the disorder, it would be advisable to assess symptoms for the other disorder.

The present study recruited twins – both identical and fraternal – as participants which allowed the researchers to conclude that half of the shared traits between the two disorders came from genetic factors, whereas the other half is likely due to environmental factors. The effect remained when researchers controlled for sex, and also when they excluded participants with an ADHD or autism diagnosis. This suggests that the overlap was not due to extreme samples.

Participants were administered a questionnaire that assessed whether they fulfilled the diagnostic criteria for autism and ADHD. The results showed that when one twin presented with symptoms suggestive of one disorder, the other twin tended to report symptoms found in the other disorder. This effect was stronger in identical twins compared to fraternal twins, likely due to the higher overlap of shared genetic information in the former.

The overlap effect found in this study showed that the symptom of repetitive behaviors found in autism corresponded most strongly with the the impulsivity and hyperactivity symptoms found in ADHD, which was supported by a similar study done in 2014. On the other hand, existing studies done on children have shown that it is the social and communication difficulties instead that corresponds most strongly with ADHD. This has led researchers to surmise that the type of symptoms that both disorders share changes with age.

However, researchers have yet to find out the reasons behind this change. A possible deduction may be that social and communication difficulties are less prominent in adults compared to children – where adults can choose their social environment, children tend to have fixed social environments, such as school.

Category(s):Adult ADHD, Adult psychological development, Attention Deficit Hyperactivity Disorder (ADHD), Autism spectrum disorders

Source material from Spectrum