As researchers continue to investigate the origins of depression, anxiety, and other mental disorders, a new study in JAMA Psychiatry has found that one in seven children in Denmark will develop some form of mental illness before they turn 18.

The paper, by researchers at Aarhus University and other institutions, looked at a database of health information collected from 1.3 million Danish children from age 0 to 18. Boys had a 15.5 percent chance, and girls a 14.6 percent chance, of being clinically diagnosed with a mental illness before age 18. Attention-deficit/hyperactivity disorder (ADHD) was the most common disorder among boys, while anxiety was most prevalent among girls. Depression and schizophrenia were also present.

Researchers also examined when children were diagnosed. Boys tended to be labeled with ADHD as young as 8 years old, while girls received the same diagnosis more frequently at 17. Boys were also diagnosed with other illnesses earlier overall.

The study was limited to Denmark, and socioeconomic factors that may influence ailments and diagnoses can vary by country. Still, researchers said these statistics may help mental health professionals prepare earlier intervention and provide young people the help they need.

[h/t Independent]