A study led by the University of Southampton has found that ADHD medications have a small effect on blood pressure and heart rate.

The research, published in The Lancet Psychiatry, looked at the cardiovascular effects of ADHD medications based on randomised controlled trials.

There have been concerns about the side effects of ADHD medications, but the new findings suggest that the benefits of taking these medications outweigh the risks.

Professor Samuele Cortese, senior lead author of the study, said: "When it comes to taking any medication, risks and benefits should always be assessed together.

"We found an overall small increase in blood pressure and pulse for the majority of children taking ADHD medications.

"Other studies show clear benefits in terms of reductions in mortality risk and improvement in academic functions, as well as a small increased risk of hypertension, but not other cardiovascular diseases.

"Overall, the risk-benefit ratio is reassuring for people taking ADHD medications."

The study, funded by the National Institute for Health and Care Research (NIHR), analysed data from 102 randomised controlled trials, including a total of 22,702 participants with ADHD.

It is estimated that ADHD affects around 4 per cent of children in the UK, with around 45 per cent of these treated with medication.

The researchers found that all ADHD medications were generally associated with overall small effects on blood pressure, heart rate, and ECG parameters.

No significant differences were found between stimulants (including methylphenidate and amphetamine) and non-stimulants (atomoxetine and viloxazine) with regard to their effects on blood pressure and heart rate.

Dr Luis Farhat said: "Our findings should inform future clinical guidelines, stressing the need to systematically monitor blood pressure and heart rate, both for stimulants and non-stimulants.

"This should be particularly relevant for practitioners who might assume that only stimulants have a negative effect on the cardiovascular system."

The researchers say that those with existing heart conditions should discuss the side effects of ADHD medications with a specialist cardiologist before starting treatment.

The research team will now look to see if some groups might be more vulnerable to cardiovascular side effects than others.