The debate on nature versus nurture has never ceased, particularly in discussions about neurodevelopmental conditions (NDCs) such as autism and attention-deficit hyperactivity disorder (ADHD). These lifelong conditions emerge in childhood, and while they mostly have genetic nature, environmental factors may play a role.
In a new thesis from Karolinska Institutet, PhD student Aleksandra Kanina at the Department of Medical Epidemiology and Biostatistics investigated the potential impact of environmental factors such as adverse life events, psychosocial adversity during pregnancy and early childhood, and neonatal jaundice on the likelihood of autism and ADHD in children. While genetic factors have long been recognized as playing a significant role in these neurodevelopmental conditions, Aleksandra's studies highlight the importance of considering environmental influences and the complexity of familial factors.
What are the most important results in your thesis?
"We found that adverse life events (ALEs) and psychosocial adversity were associated with an increased likelihood of autism and ADHD, but these links were weaker when accounting for familial relatedness, suggesting that family background might be influencing these associations. The results also pointed to the idea that much of the relationship between environmental factors and autism or ADHD diagnoses may be explained by unmeasured familial confounding rather than a direct causal effect. Additionally, we saw that neonatal jaundice was linked to autism diagnoses, but the relationship appeared to be influenced by perinatal factors like gestational age, rather than a direct environmental impact. Overall, the study underscores the importance of considering familial factors when exploring the environmental causes of autism and ADHD."
Why did you become interested in this topic?
"I was interested in the evolving paradigm in the field of neurodevelopmental conditions and wanted to contribute to a better understanding of the origins of ADHD and autism. Given the stigmatizing history of autism research, it is essential to debunk the myths surrounding the diagnosis. Parents of autistic children often blame themselves or are unfairly held accountable, making this research crucial in reducing stigma."
What do you think should be done in future research?
"I wish healthcare professionals would pay more attention to the needs of autistic individuals, especially pregnant women experiencing adverse life events. Mental and reproductive health in neurodivergent females is largely overlooked, and I truly hope this changes!"
Doctoral thesis
Aleksandra Kanina. Stockholm: Karolinska Institutet (2025), ISBN: 978-91-8017-465-7
