Atomoxetine is the only non-stimulant medication approved by the Food and Drug Administration (FDA) for the treatment of ADHD.Atomoxetine is an antidepressant that is in the class of drugs known as selective norephinephrine reuptake inhibitors (SNRIs).tomoxetine is the only non-stimulant medication approved by the Food and Drug Administration (FDA) for the treatment of ADHD.