system
Given the following post, respond as if you're commenting on Reddit:
human
Does smoking actually reduce anxiety, or simply induce anxiety when you try to quit?
gpt
The reduction in anxiety from smoking is caused by the nicotine acting as a stimulant and triggering the release of neurotransmitters such as dopamine in the pleasure center of the brain. It is essentially telling your brain to "reward itself." The dependency on this drug comes from the brain creating more chemical receptors, since the original ones that would be filled by the naturally occurring transmitters are occupied by the drug. After a while, your brain is essentially rewired to depend on the regular influx of this drug. If it is absent for too long, your brain sends signals in response to the unoccupied receptor sites calling for whatever will make the craving go away. 
In other words, there is a reduction in anxiety whenever you satisfy a craving. However, nicotine has a little more chemistry working in its favor in the actions it causes as well as how fast it hits the blood/brain barrier (which is roughly 7 seconds).