What is the mechanism of action for Selegiline in treating depression?

Selegiline's primary mechanism of action in treating depression involves the inhibition of monoamine oxidase B (MAO-B), an enzyme responsible for breaking down dopamine in the brain. By inhibiting MAO-B, Selegiline increases the availability of dopamine, which can have positive effects on mood and emotional regulation. This is particularly significant in certain forms of depression, including Parkinson's disease-related depression, where dopaminergic activity is often compromised.

The focus on MAO-B is crucial because Selegiline, at lower doses, selectively inhibits this subtype, leading to enhanced dopaminergic activity without significantly affecting serotonin or norepinephrine. This specificity means that it may have fewer dietary restrictions compared to non-selective MAO inhibitors, which are known to cause severe reactions with tyramine-rich foods.

In contrast, the other options explore mechanisms that do not accurately reflect Selegiline’s primary action. For instance, while enhancing norepinephrine synthesis could potentially contribute to antidepressant effects, it is not the primary mechanism through which Selegiline operates. Similarly, while increasing serotonin levels might be a desired outcome in depression management, it is not Selegiline's direct action. Lastly, although dopaminergic reuptake inhibition is a strategy employed by