Atomoxetine is a selective norepinephrine reuptake inhibitor primarily used to treat attention-deficit hyperactivity disorder (ADHD) in children, adolescents, and adults by increasing norepinephrine levels in the brain to improve focus, attention, and impulse control. Marketed under the brand name Strattera, it differs from stimulant medications as it is non-controlled and works gradually over weeks to alleviate ADHD symptoms through selective inhibition of presynaptic norepinephrine transporters, particularly in the prefrontal cortex. Approved by the FDA in 2002, it remains a widely prescribed option, ranking among the top medications for ADHD management in recent years. Off-label uses include addressing cognitive impairments from traumatic brain injury or subarachnoid hemorrhage. Unlike stimulants, it lacks significant abuse potential and can be stopped abruptly without notable withdrawal.