Nomifensine was primarily used as an antidepressant in the treatment of depressive disorders. It works by inhibiting the reuptake of dopamine and norepinephrine, which helps to elevate mood and improve emotional stability. This made it effective for individuals experiencing symptoms of major depression or other mood-related conditions. Additionally, it was explored for its potential in managing certain types of chronic pain due to its influence on neurotransmitter activity. In some cases, it was also studied for its role in treating attention deficit hyperactivity disorder (ADHD) by enhancing focus and reducing impulsivity. However, due to severe safety concerns and side effects, including hemolytic anemia and severe allergic reactions, nomifensine was withdrawn from the market in many countries in the 1980s and is no longer used in medical treatment.