Here's the story with coffee.
When it is poured into the body, the body reacts by doing what is needed to handle this poison.
Many different hormones including adrenalin are excreted.
The body basically gets revved up in this process.
All this inner activity causes one to be more awake.
Its a little like your riding with a friend in a car and all of a sudden he/she floors the gas peddle. Its going to make you more alert with this activity.
When the activity runs its course, the body feels drained from the exertion.
Yes coffee is addictive.
For one, its a poison to the body. The only thing we can get addicted to is a poison.
Nobody has ever gotten addicted to celery or lettuce.
The other addicting factor is the adrenalin rush.
By the way, coffee drinking is very rough on the liver. The liver is involved with this handling of a poison.
Ever notice that Starbucks coffee is a little more addictive than most.
The beans are processed in such a way as to give your body more of a kick. But the real kick comes from what your body has to do in response to drinking it.
Once the body gets worn down from repetitive poison consumption the kick becomes less and less and more and more poison is required to produce an equal effect.