Being hyperactive may be in your DNA, research suggests.
Scientists have identified more than 300 genetic mutations that raise the risk of the mental disorder by 19 per cent.
The findings, made by a team at SUNY Upstate Medical University in New York, may debunk critics who argue ADHD is just an excuse for bad behaviour.
Study identified 304 genetic mutations that are linked to ADHD (stock)
In the first study of its kind, researchers analysed the genes of 55,374 people from a global database.
Of these, 20,183 had been diagnosed with ADHD, according to the study published in the journal Nature Genetics.
A total of 304 mutations across 12 genetic locations were identified as being unique to the mental disorder.
These genetic variants overlapped with those for 44 other conditions and traits, including severe depression, anorexia, obesity, insomnia and even smoking.
The mutations are thought to affect a sufferer’s central nervous system, which then influences their brain development and nerve cell signalling.
This supports previous research, with ADHD already being associated with sleep disturbances and impulsive behaviours, such as overeating and smoking.
ADHD also shares genes that code for having children younger and multiple offspring, the study found.
The condition affects around five per cent of children and teenagers, and 2.5 per cent of adults, worldwide. It is also around four times more prevalent in boys than girls.
Previous studies have questioned the role of genetics in ADHD and pointed the finger more at environmental factors, such as poor parenting.
The mental disorder has previously been described as a ‘fad’ and an excuse for poor behaviour.
‘The diagnosis can be an easy-to-reach-for crutch,’ neurologist Dr Richard Saul told Psychology Today.
Dr Saul claims he has treated an adult diagnosed with ADHD who just needed to cut back on coffee, as well as a little girl who was being disruptive at school because she was struggling to read the blackboard.
‘I know of far too many colleagues who are willing to write a prescription for a stimulant with only a cursory examination of the patient, such as the “two-minute checklist,” for ADHD,’ he said.
Others point out ADHD symptoms may be masking conditions such as depression, which requires a different set of treatments.
But Dr Imad Alsakaf, assistant professor of psychiatry at Creighton University in Omaha, told WebMD there are ‘clear differences’ in the brain scans of people with and without the disorder.
Symptoms of ADHD typically appear at an early age and become more noticeable as a child grows. These can include constant fidgeting.
It is incurable. But a combination of medication and therapy is usually recommended to relieve symptoms and make day-to-day life easier.
It comes after a study last month warned pupils are being labelled as hyperactive and given medication when they are simply younger than others in their year.
Researchers examined the relationship between a child’s age relative to classmates and their chances of being diagnosed with ADHD.
After reviewing 17 studies, covering more than 14million children, researchers found it was more common for the youngest in a classroom to be diagnosed with ADHD.