An adult brain influenced by attention deficit disorder with or without hyperactivity (ADHD) presents changes that are comparable to those observed in persons suffering from dementia. These are the findings of a study conducted by the Geneva University Hospitals (HUG) and the University of Geneva (Unige) who demonstrates that patients with an ADHD diagnosis compared to healthy individuals in their blood have more iron in certain regions of their brains. These markers are consistently reported as characteristic of old-age-related dementies such as Alzheimer’s disease and can be measured in early stages. The study confirms that ADHD can be linked to an increased risk of developing dementia later in life and it offers first proof for a possible neurological mechanism. This important step forward is described in the magazine Psychiatry and clinical neuroscience.
ADHD is a frequent neurological disorder that affects approximately 3.5% of adults according to a study of the World Health Organization of 2008 (WHO). It is characterized by an inability to maintain attention, along with inappropriate levels of hyperactivity and impulsivity. Although symptoms generally manifest themselves during childhood and the development of education and social interactions significantly influence, its effects can continue to exist and the daily functioning in adult life adversely affect.
Elderly-related dementies affect around 55 million people worldwide, with nearly 10 million new cases a year according to WHO statistics from 2023. Alzheimer’s disease represents 60 to 70% of these cases of dementia.
Recent epidemiological studies show that adults suffering from ADHD have an increased risk of dementia at an advanced age, but the mechanism that makes ADHD a risk is not known. ”
Professor Paul G. Unschuld, head of the Geriatric Psychiatry Division of the hug, Assistantial Lecturer at the Department of Psychiatry at the Unige Faculty of Medicine and the initiator of the study
Iron and neurophilassen as indicators
The research team used an advanced method for the imaging of the brain, known as quantitative sensitivity mapping (QSM) by means of magnetic resonance image formation (MRI) to examine the iron content in the brain of 32 adults between 25 – 45 years old that is influenced by ADHD and 29 healthy persons. Neuroophilament light chain protein (NFL) levels in the blood of the participants were measured in parallel. The results of the study reveal remarkable differences in iron distribution in different brain areas of the persons affected by ADHD. In addition, a significant association was established between iron mirrors in the Cortex and NFL levels in the blood.
Iron plays an essential role in normal brain functioning, but its excessive accumulation can cause neuronal damage and lead to neurodegenerative diseases such as Alzheimer’s disease. “Excess iron in certain brain areas is often observed and is associated with increased oxidative stress that promotes neuronal degeneration,” specifies professor Paul Unschuld. At the same time, the NFL is an indicator for neuronal damage in the brain, more specifically of neuronal axons that are essential for nerve transmission. High blood levels from NFL reflect axon damage in the brain. Consequently, an increased brain iron and NFL levels may indicate an underlying neurodegenerative pathology and an increased risk of neurodegenerative dementia in old age.
These results confirm that there is a connection between ADHD and an increased risk of dementia in old age and the identification of the first neurological mechanism.
The importance of early detection and management of ADHD
These discoveries peach the way for new research to understand why people with ADHD possibly run an increased risk of dementia. Professor Paul Unschuld is of the opinion that the information provided by this study will make it possible to develop targeted prevention strategies to reduce the risk of dementia in persons affected by ADHD. This is especially important because there is a known correlation between lifestyle and changed iron values in the brain. ADHD. “
Moreover, the relationship between ADHD and dementia underlines the importance of early detection of these diseases. It also emphasizes the importance of ADHD’s proactive management in adults, not only to improve the quality of life for individuals, but also to prevent long -term consequences for cognitive health.
This study was funded by a Spark Grant awarded by the Swiss National Science Foundation (SNSF) to Professor Paul G. Unschuld.
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Journal Reference:
Berberat, J., et al .. (2025). Brain iron load and neuroaxonal vulnerability in adult lack of attention hyperactivity disorder. Psychiatry and clinical neuroscience. doi.org/10.1111/pcn.13806.