Doses are lower in adults over 55, and cardiac risks modest
STUDY: Michielsen M et al, Journal of Attention Disorders 2021;25(12):1712–1719
STUDY TYPE: Observational cohort study (electronic health record review)
FUNDING: None
Background
There are no controlled trials of stimulants in adults over age 50, so this observational study adds valuable data on what to expect.
The Study
- 113 patients aged 55 to 79 (mean age 61) treated at a specialized adult ADHD clinic in the Netherlands.
- 89 started ADHD medication; most received methylphenidate extended release.
- Cardiovascular measures, response, and side effects were recorded before and at least 7 days after the first dose.
Results
65% of patients reported a positive response to stimulants. The most common benefits were better concentration, less restlessness, and more energy.
On the cardiovascular side, methylphenidate produced a small but statistically significant increase in heart rate (69 to 73 bpm) and a slight drop in weight. Blood pressure didn’t change meaningfully at the group level, even among the nearly 30% who had a preexisting cardiovascular risk profile.
42% eventually stopped their medication, most often due to anxiety, depressive symptoms, cardiovascular complaints, or nonresponse. Only one patient stopped for clear cardiovascular reasons.
The doses were on the low side:
Limitations
- No control group, so firm conclusions about effectiveness can’t be drawn.
- High dropout rate (43%),
- Response was self-reported and not measured with a validated rating scale.
- Half the patients didn’t receive a baseline ECG.
- Follow-up timing varied across patients.
- Small numbers for dexamphetamine and dexmethylphenidate prevented any safety conclusions for those agents.
Practice Implications
- Stimulants have a reasonable safety record in this study, but notably the doses are lower than typically seen in adults. In animal studies, they cross into the brain more readily with old age, suggesting lower doses may be as effective (and safer).
- Before starting stimulants in an older patient, assess sleep, mood, anxiety, and cardiovascular status. Treat those problems first.
- Once you start a stimulant, measure blood pressure and heart rate at baseline and recheck them at every visit. An ECG before starting is reasonable in anyone with a cardiac history.
— Chris Aiken, MD
Director, Psych Partners
Editor in Chief, Carlat Psychiatry Report
