A new study published in JAMA Psychiatry finds that long-term use of ADHD drugs is linked to an increased risk of cardiovascular disease.
According to the current research, led by Le Zhang of the Karolinska Institutet in Sweden, service users are at a 4% greater risk of cardiovascular disease (CVD) for each year of ADHD drug use. The largest increase in risk for cardiovascular disease occurs in the first three years of ADHD drug use. Children and adults see a similar pattern of risk when these drugs are used long-term. The authors write:
“This large, nested case-control study found an increased risk of incident CVD associated with long-term ADHD medication use, and the risk increased with increasing duration of ADHD medication use. This association was statistically significant both for children and youth and for adults, as well as for females and males. The primary contributors to the association between long-term ADHD medication use and CVD risk was an increased risk of hypertension and arterial disease. Increased risk was also associated with stimulant medication use.”
The goal of the current research was to examine the link between the use of drugs meant to treat ADHD and the risk of developing CVD. To achieve this goal, the authors used several databases that track diagnoses, prescriptions, and demographics of people residing in Sweden. They used the National Inpatient Register for data on diagnoses, the Swedish Prescribed Drug Register for data on prescriptions, the Longitudinal Integrated Database for Health Insurance and Labour Market studies for socioeconomic data, and the Swedish Cause of Death Register for data on participant deaths.
The authors examined data from everyone living in Sweden aged 6-64 who received an ADHD diagnosis or drugs to treat ADHD between January 1, 2007, and December 31, 2020. Data on 278,027 service users were explored for inclusion in the study.
19,192 service users were excluded due to having a CVD diagnosis before using ADHD drugs, being prescribed ADHD drugs to treat something other than ADHD, and emigrating or dying before the start of the research. Of the 258,835 service users who met the inclusion criteria, 10,842 received a CVD diagnosis after using drugs meant to treat ADHD. After excluding those with short follow-up periods (3 months or less) and those without a matched control case, the authors had 10,388 service users with a cardiovascular disease diagnosis paired with 51,672 control cases (with no CVD when the research began).
In the overall sample used in the current research, ADHD drug use for 1 to 2 years is associated with a 4% – 9% increased risk of CVD. 2 – 3 years of drug use is associated with a 10% – 15% increased risk of CVD. 3 – 5 years of drug use is associated with 23% – 27% increased risk of CVD. More than five years of drug use is associated with a 20% – 23% increased risk of CVD.
For people between the ages of 6 and 24, ADHD drug use for 1 – 2 years is associated with a 5% – 8% increased risk of CVD. 2 – 3 years of drug use is associated with an 18% – 21% increased risk of CVD. 3 – 5 years of drug use is associated with 22% – 25% increased risk of CVD. More than five years of drug use is associated with a 30% – 35% increased risk of CVD.
For people between the ages of 25 – 64, ADHD drug use for 1 – 2 years is associated with a 5% – 10% increased risk of CVD. 2 – 3 years of drug use is associated with a 6% – 12% increased risk of CVD. 3 – 5 years of drug use is associated with 23% – 29% increased risk of CVD. More than five years of drug use is associated with a 16% – 19% increased risk of CVD.
The authors note that the increased risk of CVD when taking ADHD drugs was mainly present for two conditions: hypertension and arterial disease. The use of ADHD drugs for 3 – 5 years was linked to a 72% increased risk of developing hypertension and a 65% increased risk of developing arterial disease. At five years of ADHD drug use, service users are at 80% increased risk for developing hypertension and 49% increased risk of developing arterial disease. The present research found no increased risk for the use of ADHD drugs in developing arrhythmias, heart failure, ischemic heart disease, thromboembolic disease, or cerebrovascular disease.
The authors acknowledge several limitations to the current study. They used recorded diagnoses of CVD for their analyses, which could have missed some service users with CVD that had not yet been diagnosed. This means the association between ADHD drug use and CVD may be stronger than the present research indicates.
The authors used data on prescriptions of ADHD medication, but there is no guarantee that service users took their medication as prescribed. Due to confounding variables and the observational nature of the study, this research cannot speak to causality, meaning the researchers simply observed a link between ADHD drug use and CVD. They cannot say if the ADHD drugs actually caused CVD. The present research also excluded service users with pre-existing CVD. The data was collected exclusively in Sweden, so generalizability to other populations is limited. The authors conclude:
“The results of this population-based case-control study with a longitudinal follow-up of 14 years suggested that long-term use of ADHD medication was associated with an increased risk of CVD, especially hypertension and arterial disease, and the risk was higher for stimulant medications. These findings highlight the importance of carefully weighing potential benefits and risks when making treatment decisions on long-term ADHD medication use.”
Previous research has found that long-term use of ADHD drugs is linked to growth suppression. The addictive nature of these drugs also means service users can experience withdrawal symptoms when attempting to discontinue their use. ADHD drug use has also been linked to hallucinations. Adults receiving treatment for ADHD report a low quality of life, and experts have said that in most cases, the risks associated with ADHD drugs outweigh the benefits.
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