© uwe umstätter / www.globallookpress.com
Scientists appear to have conclusive proof that ADHD is a physical condition - and not just erratic behavior in children. Evidence has been revealed in scans that show structural differences in the brains of sufferers.

Attention Deficit Hyperactive Disorder (ADHD) results, in essence, in sudden bursts of hyperactivity, coupled with inattention and a frequent inability to focus. Children particularly suffer, especially with school work and relationships with parents. But the symptoms may continue into adulthood. The causes of ADHD remain disputed.

A new study, the largest ever of its kind, may shed light. The lead author, Martine Hoogman of Radboud University Medical Centre in the Netherlands, says the data "confirm that people with ADHD have differences in their brain structure and therefore suggest that ADHD is a disorder of the brain."

In a statement, she expresses hope "that this will help to reduce stigma that ADHD is 'just a label' for difficult children or caused by poor parenting."

The study involved scanning the brains of 1,713 participants purportedly with ADHD, and 1,529 participants with no signs of any psychological difficulties. All were aged four to 63. They submitted to MRI tests, which revealed the structural differences.

According to the scans, suspected ADHD sufferers have an overall smaller brain size, which also goes for five specific regions of the brain, including the amygdala - responsible for regulating emotions.

But the differences are also really hard to spot, according to Hoogman, who says the brains of one group only differed by "a few percent - so the unprecedented size of our study was crucial to help identify these."

The differences were more prominent in children than adults, and the differences in size were attributed to slower development compared to fully healthy brains.

Hoogman points to other conditions where brain size differences are commonplace, such as major depressive disorder (MDD).

Notably, no differences were found in the brain size of people who took ADHD drugs and those who did not.

The research was praised by Columbia University's Jonathan Posner as "an important contribution" to the study of the condition. However, follow-up studies are recommended, he added, according to Medical Express.

Another recent study in ADHD dates back to May last year, and posits that children with the disorder have some symptoms also found with rare forms of cancer.

There is also currently a debate on how to prescribe medication. Existing ADHD meds are very powerful, and cause a plethora of side effects, ranging from weight loss to depression and feelings of suicide. This is a particular problem for American children, who are prescribed things like Ritalin freely whenever erratic symptoms appear.

In early May, the US Centers for Disease Control and Prevention warned that doctors in the US might be overprescribing ADHD drugs for children under the age of six.

The CDC found that less than half of children diagnosed with ADHD symptoms were receiving behavior therapy, the preferred first-line of treatment for ADHD, before being given drugs.

The long-term effects of drugs like Adderall and Ritalin on the brains and bodies of young people are still under-studied, the CDC said.