Caffeine can indeed be habit-forming, but it's important to distinguish between addiction and habituation. My colleague, Robert Malenka, has pointed out that while many of us may find it hard to start our day without a hit of caffeine, we don't typically see the destructive behaviors associated with more severe addictions, such as those to substances like cocaine or opioids.
Caffeine does stimulate the release of dopamine and acetylcholine, which increase our focus, alertness, and feelings of well-being. It also increases the number of dopamine receptors in the reward pathways of the brain, making positive experiences feel even better. However, caffeine's interaction with the dopamine system is distinct from the classical dopamine pathway associated with addiction and reward.
So, while caffeine can certainly create a strong habit and some withdrawal symptoms if abruptly discontinued, it doesn't typically lead to the high addictive liability seen with substances like cocaine or opioids.