How effective is selegiline/imidopir in the treatment of depression?

Selegiline/midopir (Selegiline) was first widely used due to its outstanding effect in the treatment of Parkinson's disease. However, with the deepening of research, its unique role in the treatment of depression has gradually been confirmed. The drug selectively inhibits the activity of monoamine oxidase B (MAO-B) in the brain and reduces the decomposition of neurotransmitters such as dopamine, norepinephrine and serotonin, thereby improving the efficiency of nerve signal transmission and improving mood, motivation and cognitive performance.

Different from traditional antidepressants, the mechanism of action of selegiline is closer to the "dopamine pathway enhancement" theory. The main symptoms of many patients with depression are lack of motivation, anhedonia, and decreased attention, and these symptoms are closely related to low dopamine function in the mesolimbic system. By increasing dopamine levels, selegiline is particularly effective for patients with "low will" or "mental retardation-type depression". In addition, it also has a certain impact on norepinephrine and serotonin, so it also shows a comprehensive effect on mood regulation and anxiety relief.

In recent years, clinical studies have shown that selegiline can effectively relieve depression and slow thinking when used in patients with moderate to severe depression in the form of a transdermal patch. Compared with oral preparations, the transdermal system avoids the risk of "tyramine reaction" and provides a more stable blood concentration. It is considered a major improvement over traditional MAOI antidepressants.

Based on clinical feedback, selegiline has a relatively mild effect and usually requires continuous use for 2 to 4 weeks before significant improvement occurs. The side effects are relatively mild, with common symptoms including insomnia, dizziness, mild nausea, etc., which can be alleviated as tolerance develops. Compared with tricyclic or SSRI drugs, selegiline has fewer adverse effects on sexual dysfunction and weight changes, so it has advantages in some patients with treatment-resistant depression.

Reference: https://www.drugs.com/mtm/selegiline.html