Researchers have recently uncovered how genetic factors can influence symptoms of Attention-Deficit/Hyperactivity Disorder (ADHD), autism, and anxiety.

A global study led by King’s College London, UK, delved into the varying sensitivity of individuals to environmental factors and its impact on levels of ADHD symptoms, autistic traits, anxiety, depression symptoms, psychotic experiences, and neuroticism.

Collaborating with 23 universities worldwide, researchers analyzed data from 21,792 identical twins (10,896 pairs) across 11 studies to pinpoint genetic variants associated with environmental sensitivity. This marks the largest Genome-Wide Association Study (GWAS) of identical twins conducted to date.

They identified specific genetic factors linked to differences in environmental sensitivity within identical twin pairs. The interplay between these genetic factors and environmental exposures could elucidate variations in susceptibility to psychiatric and neurodevelopmental conditions, as detailed in the paper published in the journal Nature Human Behaviour.

Dr. Elham Assary, Postdoctoral Researcher at King’s, explained, “Differences in individuals’ sensitivity to life experiences can elucidate why the same experiences may impact mental health differently based on genetic makeup. Our results indicate that particular genetic variants can influence how environmental exposures affect psychiatric and neurodevelopmental symptoms.”

Within the genetically identical twins, researchers observed that genes associated with growth factors, crucial biological molecules in neurodevelopment, immune function, and the central nervous system, were linked to variations in autistic traits. Genes related to stress reactivity were tied to differences in depression symptoms, while genes regulating catecholamines, a group of hormones involved in stress response, were associated with variations in psychotic-like experiences.

Professor Thalia Eley, Professor of Developmental Behavioural Genetics at King’s, noted, “These findings underscore the role of genes in shaping psychiatric and neurodevelopmental traits by influencing individuals’ responses to their environment. Some individuals exhibit heightened sensitivity to their surroundings, which can be advantageous in positive circumstances but challenging in stressful situations compared to others.”