ADHD Medication and the 4% Per Year Heart Risk Study, Explained

A large Swedish study found that each additional year of ADHD medication use was associated with 4% higher odds of cardiovascular disease. The increase was concentrated in the first three years, involved mainly high blood pressure, and appeared at higher doses.¹ The risk is small for most patients and it can be monitored with a blood pressure cuff.

The study was published in JAMA Psychiatry in 2024 and has circulated widely on social media since. Reporters and patients have both asked me about it.

What the study did

Zhang and colleagues used Swedish national registers covering 278,027 people with ADHD aged 6 to 64, with data from 2007 to 2020. People with a history of cardiovascular disease before baseline were excluded. The researchers identified 10,388 people who developed cardiovascular disease and matched each of them to up to five controls of the same age and sex, 51,672 in total. They then compared how many years of ADHD medication each group had taken, up to 14 years. Median follow-up was 4.1 years, and the median age of cases was 34.6 years.¹

What it found

Source: Zhang et al., JAMA Psychiatry 2024.¹

Across the full 14 years, each additional year of use was associated with 4% higher odds (adjusted odds ratio 1.04, 95% CI 1.03 to 1.05). During the first three years the figure was 8% per year (1.08, 95% CI 1.04 to 1.11), and the risk was stable over the remaining follow-up.¹

What 4% per year means for one person

The figure is relative. It describes odds compared with people with ADHD who weren't taking medication, and 4% of a small number is a small number. The overall incidence of cardiovascular disease in this cohort was 7.34 per 1,000 person-years.¹ The paper doesn't report an absolute difference between users and nonusers.

The increase was concentrated in the first three years, after which the odds held near 23% to 27% above nonuse. This is an average across a large population. Some people will be higher and some lower, and the way to find out is to measure your blood pressure. If your blood pressure stays at a normal number, the medication is unlikely to be contributing much to your risk of a heart attack or stroke.

The association was with hypertension and arterial disease

More than five years of use was associated with 80% higher odds of hypertension (1.80, 95% CI 1.55 to 2.08). Arterial disease was elevated at three to five years (1.65, 95% CI 1.11 to 2.45). The study found no statistically significant increase in arrhythmias, heart failure, ischemic heart disease, thromboembolic disease, or cerebrovascular disease.¹

That pattern fits the pharmacology. These medications act on the sympathetic nervous system, which tightens blood vessels and raises blood pressure. In randomized trials, stimulants raise systolic pressure by roughly 2 mm Hg and pulse by 4 to 6 beats per minute over several weeks.² Blood pressure that sits a little higher for years damages the endothelium, the lining of the vessel. A long-term rise in hypertension diagnoses is the result I would expect.

Dose mattered

The per-year association was statistically significant only among people whose average dose was at least 1.5 times the defined daily dose. For methylphenidate, one defined daily dose is 30 mg, so the threshold corresponds to 45 mg a day or more.¹ Using the lowest dose that controls symptoms is a practical way to act on this finding.

Why methylphenidate and Vyvanse stood out

Methylphenidate was associated with higher odds at three to five years (1.20, 95% CI 1.10 to 1.31) and beyond five years (1.19, 95% CI 1.08 to 1.31). Lisdexamfetamine (Vyvanse) was associated with higher odds at two to three years (1.23, 95% CI 1.05 to 1.44); beyond three years the estimate was 1.17 and no longer statistically significant. Atomoxetine was significant only in the first year of use (1.07, 95% CI 1.01 to 1.13).¹

Pharmacology likely contributes. Lisdexamfetamine is an amphetamine. It blocks the reuptake of norepinephrine and also pushes more of it out of the nerve cell, so the sympathetic effect is stronger. I'd expect mean blood pressure on these medications to run somewhat higher.

Why the risk was 27% at three to five years and 23% after five

The two estimates have overlapping confidence intervals (1.17 to 1.39 and 1.12 to 1.36), so the dip is most likely statistical noise. The overall trend is more informative than any single figure. Other explanations are possible. People who stay on medication for many years may have closer medical follow-up and better-treated blood pressure, and people with shorter exposure may have been taking higher doses.

What the study can't tell us

This was an observational study, and it cannot show that the medication caused the cardiovascular disease. People with ADHD already carry higher cardiovascular risk. In a separate cohort of 5.4 million Swedish adults, ADHD was associated with about twice the risk of cardiovascular disease, and 65% higher risk after adjustment for smoking, obesity, diabetes, sleep problems, and psychiatric conditions.³

The people who take medication longest and at the highest doses likely have more severe ADHD, with more stress and more of those background risks. Registers don't fully capture ADHD severity, diet, or exercise. People on a stimulant also see a doctor regularly and have their blood pressure measured more often, which may lead to more hypertension diagnoses. While there's a clear physiological explanation for a medication effect, some of the association likely belongs to the condition and to how closely treated patients are watched.

How this changes what I do

ADHD was long treated as a childhood condition, so decades of adult exposure weren't something the field thought about. They are now. In my adult patients I pay closer attention to baseline blood pressure and to the usual cardiovascular risk factors: existing hypertension, diabetes or prediabetes, and age.

When blood pressure is high in someone who's clearly benefiting, the first move is usually to treat the blood pressure. Lowering the dose or changing the medication are also options. Medicine manages cardiovascular risk factors very well, and antihypertensives are effective. Regular aerobic exercise lowers blood pressure and also improves ADHD symptoms.

The study is also a reason to be judicious about who starts medication. These drugs are controlled substances and they aren't harmless. Starting one makes sense when the diagnosis has been carefully established and there's a specific problem the medication is expected to improve. I ask every patient how we'd know it's working: fewer careless mistakes, fewer interruptions, better performance reviews, a teacher's report. If nothing you can name is getting better over several months, the risk isn't worth taking.

Stopping medication carries its own risks

Untreated ADHD raises the risk of depression, anxiety, substance use, and car accidents. In a study of 148,578 people with ADHD, starting medication was associated with 21% lower all-cause mortality (hazard ratio 0.79, 95% CI 0.70 to 0.88).⁴ That finding is observational too, and deserves the same caution as the cardiovascular result. Taken together, the evidence supports staying on effective treatment and monitoring blood pressure.

Chest pain, fainting, or shortness of breath during treatment needs immediate medical assessment. Seek emergency care for severe symptoms.⁵

Related: Effects of ADHD medication on the heart · ADHD medication with high blood pressure · ADHD and life expectancy · Outcomes of untreated ADHD