Inattention symptoms linked to lower cognitive performance in older adults

Attention-Deficit/Hyperactivity Disorder is frequently stereotyped as a condition affecting school-aged children who cannot sit still in class. However, symptoms of this neurodevelopmental disorder often persist well into adulthood and later life.

A new study indicates that symptoms of inattention are linked to lower performance on memory and mental processing tasks in older adults. This association appears to remain consistent regardless of whether an individual is in their late fifties or their early eighties. The findings were published in the Journal of Attention Disorders.

Marrium Mansoor, a researcher at Virginia Tech, led the investigation to bridge a gap in current medical understanding. Most existing literature focuses on the cognitive impacts of the disorder in children or young adults. When researchers do study cognition in older populations, the focus typically shifts almost exclusively to dementia or mild cognitive impairment.

This leaves a blind spot regarding how Attention-Deficit/Hyperactivity Disorder (ADHD) manifests in seniors. Mansoor and her colleagues sought to determine if the specific cognitive deficits seen in younger patients are also present in the aging population of the United States.

The research team aimed to disentangle specific ADHD symptoms from general aging or other mental health conditions. They were particularly interested in two distinct categories of symptoms. The first category is inattention, characterized by difficulty focusing or sustaining attention. The second is hyperactivity and impulsivity, characterized by restlessness or acting without thinking. The researchers also wanted to verify if depression was actually the root cause of cognitive issues, rather than ADHD itself.

To investigate these questions, the team utilized data from the Health and Retirement Study. This is a large-scale, longitudinal project that surveys a representative slice of the American population over the age of 50. The researchers selected a sample of approximately 1,300 adults for their analysis. The data for this specific study was collected during the 2016 wave of the survey.

The participants were divided into three specific age bands to allow for detailed comparison. The first group consisted of middle-aged adults between 55 and 64 years old. The second group, labeled “young-old,” included those between 65 and 74. The final group, the “middle-old,” ranged from 75 to 84 years of age.

Participants completed a self-report questionnaire to assess their ADHD symptoms. This tool, known as the Adult ADHD Self-Report Scale, asks individuals to rate how often they experience specific problems. For example, it asks about trouble wrapping up the final details of a project or difficulty keeping appointments. The researchers assessed depression using a separate standard scale.

Cognitive performance was measured using a battery of tests designed to evaluate different mental functions. One such test is known as “Serial 7s.” In this assessment, participants are asked to start at the number 100 and subtract the number seven repeatedly. This task requires strong working memory and sustained attention. It forces the brain to hold a number in mind while performing a calculation.

Another test involved “Immediate Recall.” The interviewer read a list of 10 random words to the participant. The participant then had to repeat as many words as they could remember, in any order. This measures episodic memory, which is the ability to recall specific events or information recently learned. A “Delayed Recall” test asked participants to remember those same words after a five-minute interval.

The researchers also used a “Number Series” test. This involves showing the participant a sequence of numbers with one missing. The participant must identify the pattern and fill in the blank. This tests fluid intelligence, or the ability to reason and solve new problems independent of previously acquired knowledge.

The study revealed a clear statistical link between inattention and specific cognitive struggles. Participants who reported higher levels of inattention symptoms performed worse on the Serial 7s task. They also scored lower on the Immediate Recall test. This suggests that the inability to focus attention directly hampers the brain’s ability to process numbers and encode new memories.

The researchers used statistical modeling to determine if these associations changed as people got older. They compared the strength of the relationship between symptoms and cognitive scores across the three age groups. They found that the “constrained model” provided the best fit for the data. In statistical terms, this means the relationship between inattention and cognitive performance did not vary by age. The negative impact of inattention on memory and processing was just as strong for an 84-year-old as it was for a 55-year-old.

The findings regarding hyperactivity and impulsivity were less consistent. In some initial statistical models, high hyperactivity scores seemed linked to worse performance on delayed memory tasks for the oldest group. However, in the final, most accurate model, this connection was not statistically significant. This reinforces the idea that inattention is the primary driver of cognitive difficulties in this context.

A critical aspect of this study was its treatment of depression. Previous research conducted in Australia and the Netherlands suggested that depression might be the real reason older adults with ADHD symptoms struggle cognitively. Depression often causes lack of focus and memory issues. However, Mansoor and her team found that the link between inattention and poor cognition remained even when they accounted for depressive symptoms.

The authors suggest these results have practical applications for doctors and geriatric specialists. Older adults reporting memory problems are often evaluated for dementia. This study implies that some of these patients might be dealing with undiagnosed or unmanaged ADHD. Interventions that focus on memory strategies, such as the “method of loci” or other mnemonic devices, could be beneficial.

There are limitations to this research that require consideration. The study relied on self-reported symptoms rather than clinical diagnoses made by a psychiatrist. Older adults might over-report or under-report their symptoms based on their perception of what is normal aging. Additionally, the study excluded people with a diagnosis of dementia or Alzheimer’s disease.

Another potential limitation is a concept called survival bias. The authors note that individuals with severe ADHD often have lower life expectancies due to accidents or comorbid health issues. As a result, the “middle-old” group in this study might represent a healthier subset of the population. Those with the most severe impairments may have passed away before reaching that age bracket.

The study also used cross-sectional data, meaning it looked at one specific point in time. It did not track the same individuals over decades to see how their specific cognitive trajectory changed. Future research would benefit from following individuals from middle age into late adulthood. This would help clarify if ADHD symptoms accelerate cognitive decline or simply lower the baseline of performance.

The researchers emphasize that cultural context matters. The difference between their findings and European or Australian studies suggests that the environment plays a role. Different healthcare systems and diagnostic norms may influence how these symptoms present in older populations.

Mansoor and her colleagues conclude that clinical awareness is vital. ADHD is not a condition that simply disappears after retirement. As the population ages, distinguishing between neurodevelopmental symptoms and neurodegenerative disease will become a key challenge for healthcare providers.

The study, “Self-Reported ADHD Symptoms and Cognitive Performance in a National Sample of US Older Adults,” was authored by Marrium Mansoor, Rosanna Breaux, Tae-Ho Lee, and Benjamin Katz.