New York, Nov 12 (IANS): Children and teenagers with abnormal heart rhythms (cardiac arrhythmias) are more likely to have depression, anxiety and attention deficit hyperactivity disorder (ADHD) as compared to those of similar ages without chronic medical conditions, researchers have warned.

"This may be the first study of this size looking at children and teenagers with various cardiac arrhythmias that have been diagnosed with or are taking medication for anxiety and depression," said study's lead author Keila N. Lopez from Baylor College of Medicine in the US.

Higher rates of depression, anxiety and ADHD have previously been described in young adults born with structural heart defects (congenital heart disease).

For the study, the researchers analysed the records of more than a quarter of a million children admitted to or seen in the emergency room of Texas Children's Hospital between 2011 and 2016.

They reviewed data on more than 7,300 children with abnormal heart rhythms and compared them to children with congenital heart disease, cystic fibrosis, sickle cell disease and children with none of these chronic conditions (controls).

"We chose cystic fibrosis and sickle cell disease because they are chronic diseases that are managed with medications and usually involve multiple hospitalisations," Lopez said.

They found more than 20 per cent of kids with abnormal heart rhythms, congenital heart disease and cystic fibrosis had been diagnosed with or prescribed medication for depression and/or anxiety, compared with five per cent of children with sickle cell disease and three per cent of the control group.

Kids with abnormal heart rhythms were nine times more likely to be diagnosed or treated for anxiety and depression and almost five times more likely to be diagnosed or treated for ADHD, compared to kids without any of the identified chronic diseases in the study.

Kids with abnormal heart rhythms were one and a half times as likely to be diagnosed or treated for anxiety and depression than those with cystic fibrosis, and more than five times as likely to be diagnosed or treated for anxiety and depression than those with sickle cell disease, the study said.

The study is scheduled to be presented at the American Heart Association's Scientific Sessions 2019 -- November 16-18 in Philadelphia, US.