ADHD drugs have wider life benefits, study suggests

Drug treatment can help people newly diagnosed with ADHD (attention deficit hyperactivity disorder) to reduce their risk of substance misuse, suicidal behaviour, transport accidents and criminality, a study suggests.

These issues are linked to common ADHD symptoms such as acting impulsively and becoming easily distracted.

Some 5% of children and 2.5% of adults worldwide are thought to be affected by the disorder - and growing numbers are being diagnosed.

The findings, published in the British Medical Journal (BMJ), confirm the wider potential benefits of drug treatment and could help patients decide whether to start medication, the researchers say.

Having ADHD means the brain works differently to most other people's.

Symptoms can include difficulties concentrating and sitting still, having high energy levels and being impulsive.

Despite the surge in people asking for help, the disorder is not becoming more common. Last year a BBC investigation found long waits for assessment in the UK.

People are only diagnosed if the symptoms cause at least a moderate impact on their lives.

The most commonly prescribed drugs, called stimulants, help manage everyday symptoms but there has been limited evidence of longer-term benefits for people's behaviour, while well-publicised side-effects, such as headaches, loss of appetite and trouble sleeping, have sparked debate on their safety.

This BMJ study was based on 148,500 people aged six to 64, with ADHD in Sweden.

Some 57% started drug treatment and, of these, methylphenidate (also known as Ritalin), was prescribed, to 88%.

The researchers, from Southampton University and the Karolinska Institute in Stockholm, found taking ADHD medication was linked to reductions of first-time instances of:

• suicidal behaviour - 17%
• substance misuse - 15%
• transport accidents - 12%
• criminal behaviour - 13%

When recurrent events were analysed, the researchers found ADHD medication was linked to reductions of:

• 15% for suicide attempts
• 25% for substance misuses
• 4% for accidental injuries
• 16% for transport accidents
• 25% for criminal behaviour

"Oftentimes there is no information on what the risks are if you don't treat ADHD," said Prof Samuele Cortese, study author and professor of child and adolescent psychiatry at University of Southampton.

"Now we have evidence they [drugs] can reduce these risks."

This could be explained by medication reducing impulsive behaviour and lack of concentration, which might reduce the risk of accidents while driving and reduce aggressive behaviour which could lead to criminality.

The researchers say the study was designed to be as robust as possible but cannot rule out the possibility the results were affected by factors such as people's genes, lifestyles and the severity of their ADHD.

Accessing the right medication for ADHD in many countries is not easy, with some drugs in short supply. In the UK waiting times to see specialists after diagnosis in order to access drugs can be several years.

Prof Stuart Kinner, head of the Justice Health Group at Curtin University in Western Australia, said the research demonstrated "the diffuse benefits of ADHD diagnosis and treatment".

"Failure to diagnose and treat ADHD can lead to self-medication with alcohol or other drugs, poor mental health, injury, and incarceration," he said.

"Too many people with undiagnosed ADHD end up in the criminal justice system, where their condition may remain undiagnosed and untreated."

Ian Maidment, professor in clinical pharmacy at Aston University, said the study "adds to our understanding of the potential benefits of these drugs".

However, he said the research did not assess whether patients actually took their medication or the impact of different doses.