Attention-deficit hyperactivity disorder (ADHD) does not disappear with age, new research shows. A study at the VU University Medical Centre in Amsterdam, the Netherlands, finds that ADHD affects about three percent of over-60s.
The researchers, led by Marieke Michielsen, gave a questionnaire to 1,494 people aged 60 to 94 taking part in a long-term aging study. The 231 participants who displayed the most symptoms were invited for a longer, more detailed diagnostic interview, after which the rate of ADHD was estimated to be 2.8 percent.
Michielsen said the rate was higher in those aged 60 to 70 (at four percent) than those aged 70 to 94 (2.1 percent).
She said, “There are several possible explanations for this. One may be that people’s symptoms of ADHD diminish with increasing age. Other explanations may be that the diagnostic interview used is not sensitive enough to detect ADHD in people over 70, or even that people with ADHD have a lower life expectancy compared to people without ADHD.”
She added, “ADHD affects three percent to seven percent of school-aged children, and about 4.4 percent of adults. However, little is known about ADHD in old age and this is the first epidemiological study on ADHD in older people. With a prevalence of 2.8 percent, our study demonstrates that ADHD does not face or disappear with age.”
The study is published in the British Journal of Psychiatry.
The team pointed out that previous studies indicate that ADHD is more common among men than women, but the rate was equal in this study.
They write that when ADHD was first recognized, it was thought to only be present in childhood, and very few studies focused on the condition in old age. It has “a profound impact on the lives of adults,” they explain.
“Those afflicted often work below their intellectual level, have problems in relationships and social contacts, have problems organising their daily lives, are more likely to have accidents, more often have co-existing psychiatric disorders, and more often display antisocial behavior compared with adults without ADHD.”
In older age, ADHD may also be a risk factor for significant impairment and require specific treatment. Credible data on its prevalence is therefore vital. Older people with ADHD in this study reported impairment due to the symptoms in several areas of functioning, “meaning that ADHD remains an important cause of impairment in old age,” said the authors.
But they add, “Another striking finding is that older adults with ADHD did not differ in living situation, level of education, and income compared with older adults without ADHD. Given the and impact of the ADHD, one might have expected that older adults with ADHD would experience impairments in these three areas.”
However, the respondents themselves did report that their ADHD had a negative impact on many areas of functioning, currently and in childhood.
“Although many unresolved issues remain, the study demonstrates clearly that ADHD in older age is a topic very much worthy of further study,” the researchers conclude.
A slightly more recent study of ADHD in older age has found that ADHD symptoms do decrease with age, and the links between symptoms, mood disorders, and cognitive performance also change. The study compared ADHD symptoms and cognitive ability in 3,443 middle-aged (48 to 52 years) or older-aged (68 to 74 years) men and women. Symptoms were measured using the adult ADHD Self-Report Scale.
Older adults showed significantly lower levels of ADHD symptoms, report the researchers from The Australian National University, Canberra, Australia. They say that 2.2 percent of the older group reached a score of 14 (previously used as for ADHD diagnosis) compared with 6.2 percent of the middle-aged group. Men and women were comparable for symptom levels.
The researchers go on to say that higher ADHD symptoms were associated with poorer cognitive performance in the middle-aged group. But surprisingly, higher levels of inattention symptoms were linked with better verbal ability in both age groups. What’s more, greater hyperactivity was associated with better task-switching abilities in older adults.
Details of the study appear in the journal PLoS One.
The team said, “Our results suggest that ADHD symptoms decrease with age and that their relationships with co-occurring mood disorders and cognitive performance also change. Although symptoms of depression are lower in older adults, they are much stronger predictors of cognitive performance and likely mediate the effect of ADHD symptoms on cognition in this age group.
“These results highlight the need for age-appropriate diagnosis and treatment of co-existing ADHD and mood disorders.” They add that better treatment “might contribute to promoting cognitive health in late-life.”
Michielsen, M., et al. The prevalence of attention-deficit hyperactivity disorder in older adults in The Netherlands. British Journal of Psychiatry, 9 August 2012, doi: 10.1192/bjp.bp.111.101196
Das, D., Cherbuin, N., Easteal, S., Anstey, K. Attention Deficit/Hyperactivity Disorder Symptoms and Cognitive Abilities in the Late-Life Cohort of the PATH through Life Study. PLoS One, 28 January 2014 doi: 10.1371/journal.pone.0086552