For over 25 years, ADHD research has been dominated by the genetic determinism model, which attributes ADHD primarily to inherited genetic factors. This model has influenced diagnostic frameworks, treatment pathways, and societal perceptions of ADHD. However, fissures are emerging in this overly simplistic narrative as science advances. Many leading researchers now emphasise the importance of environmental factors and gene-environment interactions, challenging the deterministic view. This post critiques the genetic determinism model by examining its central claims and providing a more nuanced explanation that better aligns with the available data. The quote from Novo Organum describes the tendency to see patterns and causal relationships where none exist.
Genetics Are Only Part of the Puzzle
A prevailing belief in ADHD research is that specific genetic variations are directly responsible for ADHD. However, if genes were the sole cause, much of what we know about this disorder wouldn’t make sense. For example, why has ADHD prevalence increased dramatically over the past few decades? Genes don’t change that quickly, but environments do.
Consider genes as a piano. A piano holds the potential for beautiful symphonies but does not produce music unless someone plays it. The environment acts as the pianist, determining which keys are pressed, in what order, and with what intensity. Just as symphonies vary depending on their performance, ADHD symptoms emerge when specific genes interact with distinct environmental factors. While genetics may predispose an individual to ADHD, environmental influences—such as prenatal stress, toxins, or neuroinflammation—are crucial in determining whether those genetic predispositions are manifested.
Flawed Interpretations of Heritability
Proponents of genetic determinism frequently highlight that ADHD has a heritability rate estimated between 74% and 80%. However, it’s important to note that heritability…