Children who have attention deficit hyperactivity disorder may face a greater risk for depression in adolescence, a new study finds. University of Maryland researchers discovered kids diagnosed with ADHD between four and six years old had higher depression rates between the ages of nine and 18.

Also, children with ADHD were nearly eight times more likely than their peers to have made a suicide plan at least once. In addition, about 18-percent actually tried to kill themselves. Researchers say when depression occurs at the same time as ADHD, it appears to begin at an earlier age, last longer and is more severe.