ADHD medication unlikely to raise self-harm risk, Aston study finds

Medication for attention deficit hyperactivity disorder is unlikely to increase the risk of self-harm, according to a large international study led by Aston University in Birmingham.

The research found that the risk of self-harm among people with ADHD was highest before they started taking medication, rather than after treatment began.

A long-standing worry

Millions of adults and children around the world have ADHD. Earlier studies of ADHD medication produced conflicting results about self-harm, and those concerns can affect whether people start or continue treatment, even though more recent research has been more reassuring.

The study was led by Dr Adrienne Chan, a pharmacy lecturer, and Regius Professor Ian Wong, of the Aston Pharmacy School. It is one of the largest multinational studies of ADHD medication safety to date.

460,000 people in five health systems

The team analysed records from more than 460,000 people in Hong Kong, New Zealand, South Korea, Taiwan and the UK who had started ADHD medication and had a record of self-harm between 2001 and 2020.

They compared three periods: the 90 days before treatment began, the first 90 days of treatment, and the rest of the treatment period, with times when people were not taking medication. Because each person was compared with themselves at different times, the method helps to rule out differences between individuals.

In all five health systems, the highest risk of self-harm came in the 90 days immediately before people started treatment. The risk after treatment began was lower, although still higher than when people were not on medication. The researchers say the consistent pattern does not support the idea that ADHD medication is the main driver of self-harm.

"An opportunity for earlier intervention"

"People often worry that ADHD medication itself increases the risk of self-harm," Dr Chan said. "What our findings suggest is that many people are already at their highest risk before treatment even begins. This highlights an important opportunity for earlier intervention. Recognising that vulnerable period could help us provide support earlier, when it may make the greatest difference."

The researchers say people with ADHD should be closely monitored, especially those whose symptoms are getting worse before they start treatment, so that help can be given before self-harm happens.

Professor Wong said the study had brought together five health systems using a common approach, while keeping each country's patient data securely within its borders. "It demonstrates how international collaboration can generate robust evidence to improve patient care while respecting patient privacy and the highest standards of data governance," he said.

The team worked with partners including University College London, the University of Hong Kong and the University of Auckland. They have created an international research platform that will now look at other questions, including what happens when people stop or restart treatment, and whether ethnicity and deprivation contribute to inequalities in ADHD care.

The study is published in BMJ Mental Health. Anyone who is struggling can contact Samaritans free, day or night, on 116 123.