ADHD, CD, and ODD: Systematic review of genetic and environmental risk factors.
DNA, not bad homes, is the main engine driving ADHD-ODD-CD triads.
01Research in Context
What this study did
The team hunted every paper that asked why ADHD, ODD, and CD travel together.
They kept only studies that compared genes with environment.
In the end they pooled family, twin, and gene studies to see which force wins.
What they found
Genes carry most of the weight.
Environment helps, but DNA sets the stage for ADHD plus ODD or CD.
A child who is born with strong ADHD risk is also prone to later rule-breaking.
How this fits with other research
Dumont et al. (2014) seems to disagree. They show that home stress keeps conduct problems alive in typical kids and in kids with ID.
Look closer: in their ASD group, conduct problems stayed high even when home life was calm.
So genes still rule in ASD, matching Andreia’s big picture. The clash melts away when you split the groups.
Takeda et al. (2012) adds detail: older age and harsher ADHD symptoms raise the odds of extra externalizing disorders.
Rice et al. (2015) and Berkovits et al. (2014) give concrete gene examples—DRD4 and DAT1 alleles nudge ADHD traits in Down syndrome and in ASD.
Why it matters
When you see a client with ADHD who is sliding into defiance, think genes first.
Keep screening for family history of ADHD, ODD, or CD.
Use that info to start behavior plans early, before conduct patterns hard-wire.
Also share the genetic angle with parents—it lowers blame and boosts teamwork.
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02At a glance
03Original abstract
This review aims to analyze the relationships between Attention-Deficit Hyperactivity Disorder (ADHD), Oppositional Defiant Disorder (ODD), and Conduct Disorder (CD), particularly regarding the relative importance of genetic and environmental factors in the development of these disorders. Studies that examined at least two of these disorders were obtained from multiple databases, following the procedures of the Cochrane Collaboration initiative. Of the 279 documents obtained, nine were retained for in-depth analysis and were considered eligible for inclusion. In addition, eight studies from the manual search were included. The objectives, methodological aspects (sample and instruments), and the main conclusions were extracted from each study. Overall, the results suggest that (a) the causes for the onset and maintenance of these disorders are more associated with genetic factors than environmental factors, although the importance of the latter is recognized, and (b) children with ADHD have a predisposition to manifest behaviors that are common to ODD and CD, including the antisocial behavior that these children often display.
Research in developmental disabilities, 2018 · doi:10.1016/j.ridd.2017.12.010