Doctors often hesitate to prescribe common attention-deficit/hyperactivity disorder (ADHD) medicines to teenagers who are also struggling with alcohol or drug use. The intention is usually caution. But a large new study suggests that this widely followed approach may actually put young people at greater risk of serious harm — and even death.

Researchers analysing the health records of more than 1.2 million adolescents and young adults aged 15–25 found that continuing treatment for ADHD significantly improved health outcomes for those who also had substance use disorders. The findings, published in the Journal of the American Academy of Child and Adolescent Psychiatry, indicate that proper ADHD treatment was linked to about a 30 per cent lower risk of death over five years.

ADHD is a neuro-developmental condition that affects attention, impulse control and activity levels. Studies suggest that around 12–13 per cent of adolescents in the United States live with the disorder. Symptoms such as difficulty concentrating, restlessness and impulsive behaviour can interfere with school, work and relationships.

However, young people with ADHD are also more likely to develop substance use disorder, which refers to dependence on substances such as nicotine, alcohol, cannabis, cocaine or opioids.

Treating both conditions together can be challenging. Doctors often worry that prescribing stimulant medicines — the most effective drugs used to treat ADHD — might worsen substance misuse because these medications act on the brain’s central nervous system.

The new research suggests those fears may be misplaced.

“For young adults with ADHD and substance use disorder, appropriate treatment for ADHD could potentially save lives,” said Raman Baweja, professor of psychiatry and behavioural health at Penn State College of Medicine and the study’s first author. “Clinicians shouldn’t hesitate to provide evidence-based ADHD treatment when it is indicated.”

Stimulant medicines, such as those commonly prescribed for ADHD, work by increasing certain chemical signals in the brain that improve focus and self-control. These medicines are considered the first-line treatment, meaning they are usually the most effective option for reducing ADHD symptoms.

Yet the study revealed that young people diagnosed with both ADHD and substance use disorders were significantly less likely to receive these medications.

Among roughly 288,000 individuals identified with both conditions, researchers found that prescriptions for ongoing stimulant treatment fell by about 15 per cent, while new stimulant prescriptions dropped by more than 17 per cent after a substance use disorder diagnosis.

Despite this decline in prescribing, the study found clear benefits when treatment continued.

Young people who received ADHD medications — whether stimulant or non-stimulant — experienced fewer hospital admissions, fewer emergency room visits, and fewer accidental overdoses. They were also less likely to report suicidal thoughts or attempt suicide compared with those who received no ADHD treatment.

Patients treated with stimulant medicines showed even stronger improvements, including a 4 per cent reduction in suicidal thoughts and attempts compared with those using non-stimulant alternatives.

Experts say the findings highlight a major treatment gap. Up to half of individuals with ADHD may develop substance use disorder, and having both conditions together can significantly worsen health outcomes.

“Although CNS stimulants are first-line, evidence-based treatments for ADHD, some clinicians appear hesitant to prescribe them in patients with substance use disorder,” Baweja said. “Our findings suggest that, when used appropriately, treating ADHD — including with stimulants — can be associated with significantly better outcomes.”

Researchers believe clearer clinical guidance could help doctors balance the risks of misuse with the proven benefits of treatment. Further studies are now examining how factors such as age, gender and type of substance use influence treatment decisions.

For many families dealing with ADHD and addiction at the same time, the message from the new research is straightforward: avoiding treatment may be far more dangerous than continuing it under medical supervision.