What physiological effect does smoking have that might help alleviate symptoms of depression?

Smoking has multiple physiological effects on the brain and body, one of which is related to the activity of monoamine oxidase (MAO), an enzyme that breaks down neurotransmitters like serotonin and dopamine. Smoking tobacco is known to inhibit MAO activity, which can lead to increased levels of these neurotransmitters in the brain.

By reducing the breakdown of serotonin and other monoamines, the inhibition of MAO could potentially enhance mood and alleviate some symptoms of depression. This effect might be why individuals with depression sometimes report a temporary improvement in mood after smoking. However, it's important to note that while the acute effects of smoking might bring some relief, the long-term impact of smoking on mental and physical health is overwhelmingly negative.

In contrast, while increased serotonin levels, dopamine release, and reduced cortisol levels may also influence mood and depression, they do not have the same direct relationship with the inhibition of MAO that smoking offers. The specific mechanism through which smoking affects MAO activity highlights its unique role in influencing neurotransmitter dynamics and how those changes can temporarily mask depressive symptoms.