Scientists have identified a significant connection between genetic predisposition to Attention-Deficit/Hyperactivity Disorder (ADHD) and the development of Alzheimer’s Disease (AD) pathology, according to a new study published in Molecular Psychiatry. This research marks the first definitive scientific correlation between ADHD and cognitive decline, raising important questions about long-term brain health in individuals with ADHD.
The Study Design and Key Findings
Researchers at the University of Pittsburgh Medical Center (UPMC) analyzed data from 212 cognitively healthy adults aged 55 to 90. Participants were assessed for genetic liability to ADHD using polygenic risk scores (ADHD-PRS), but none had a formal ADHD diagnosis. Over six years, participants underwent repeated cognitive tests, including:
- Amyloid-β PET scans: To detect amyloid plaque buildup, a hallmark of AD.
- Cerebrospinal Fluid (CSF) analysis: Measuring phosphorylated tau (p-tau) levels, an indicator of neuronal damage.
- Brain MRI scans: To track changes in brain volume and structure.
- Neuropsychological assessments: Evaluating memory, executive function, and other cognitive abilities.
The study revealed that individuals with a higher genetic risk for ADHD experienced greater cognitive decline over time, especially if they also showed signs of amyloid plaque buildup in the brain. The combined effect of high ADHD-PRS and amyloid deposition was more damaging to cognition than either factor alone. Higher genetic liability to ADHD correlated with elevated p-tau levels in CSF, reduced gray matter density, and brain atrophy in frontal and parietal regions – but only in individuals with amyloid deposits.
Why This Matters
The findings are significant because ADHD is increasingly diagnosed in adults (particularly women), and Alzheimer’s disease is expected to surge by 95% by 2050. This research suggests that genetic vulnerability to ADHD may interact with AD pathology, accelerating cognitive decline in some individuals. The study also highlights a critical gap in current research: most genetic studies on both ADHD and Alzheimer’s have focused primarily on white populations, limiting generalizability.
What’s Next?
Lead researcher Dr. Douglas Leffa emphasizes the need for further studies tracking individuals diagnosed with ADHD over time to confirm the link between the disorder and late-onset Alzheimer’s. He also stresses the importance of including more diverse populations in future research to understand how race may influence this genetic association.
Protecting Cognitive Health
While genetic predisposition plays a role, lifestyle factors remain crucial for brain health. Regardless of ADHD status, individuals can mitigate cognitive decline by:
- Maintaining regular medical checkups.
- Avoiding smoking.
- Exercising regularly.
- Managing blood pressure and blood sugar.
- Eating a balanced diet rich in whole foods.
- Prioritizing sleep.
- Staying socially engaged.
The study reinforces that cognitive decline is complex, and a proactive approach combining genetic awareness with healthy lifestyle choices is essential for long-term brain health. Further research will refine our understanding of this connection, potentially paving the way for targeted interventions to protect cognitive function in individuals at risk.
