Older adults with attention-deficit/hyperactivity disorder (ADHD) may be particularly vulnerable to the harmful effects of vascular damage, according to a report published today in The American Journal of Geriatric Psychiatry.
The small study revealed that while older adults with ADHD had less vascular damage in their brains than a matched group of older adults without ADHD, the impact of vascular damage on memory or executive function was greater in adults with ADHD than those without.
The findings suggest “ADHD lowers the threshold for experiencing the harmful effects of late-life brain pathology, and that older adults with ADHD are more sensitive to smaller degrees of cellular brain change,” wrote Brandy L. Callahan, Ph.D., of the University of Calgary and colleagues.
The study included 39 older adults (average age 63) with ADHD from a neurology clinic and 50 age- and gender-matched adults without ADHD. Both groups included participants with and without cognitive impairment. All participants were given a comprehensive neuropsychological assessment and underwent an MRI to identify white matter hyperintensities (WMHs), lesions which indicate nerve fibers damaged by vascular events such as inflammation or hemorrhages. Studies have suggested that WMHs are associated with cognitive problems.
Overall, the adults with ADHD and matched controls had similar performance scores on their neuropsychological tests, though adults with ADHD had slower processing speeds. Yet, the average volume of WMHs was significantly lower in the adults with ADHD compared with adults without ADHD (1,774 mm3 vs. 3,800 mm3).
Adults with ADHD who had higher WMH levels had significantly lower scores on tasks related to short-term verbal memory, short-term visual memory, long-term verbal memory, processing speed, and executive functioning than those with lower WMH levels. Adults without ADHD with higher levels of WMH also had lower cognitive scores, but the rate of decline was less pronounced.
“Given the results of the present study, it will be important to conduct additional work to determine the extent to which stimulant medication use in older adults with ADHD impacts vascular health,” Callahan and colleagues continued, noting that these medications increase heart rate and blood pressure. “[D]ecreases in cerebral small vessel integrity will likely have compounded effects on cognition in this population.”
To read more on this topic, see the Psychiatric News article “Symptoms, Impaired Function of ADHD Often Persist Beyond Childhood.”
(Image: iStock/MyndziakVideo)
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