Radafaxine hydrochloride is primarily used in the treatment of major depressive disorder (MDD) due to its potent norepinephrine-dopamine reuptake inhibitor (NDRI) properties. It helps alleviate symptoms of depression by increasing the levels of norepinephrine and dopamine in the brain, which are neurotransmitters associated with mood regulation. Additionally, it has shown potential in managing fatigue and improving cognitive function in patients with depression or other related conditions. Its application is also being explored in the treatment of attention deficit hyperactivity disorder (ADHD) and as an aid in smoking cessation, owing to its ability to modulate dopamine pathways. The compound is well-tolerated in clinical settings, making it a promising option for patients who do not respond adequately to other antidepressants.