That's called chemical dependence and it's the point I'm trying to make. Dependence is not addiction. Addiction means wanting is hijacked, not that stopping is aversive.
Addiction and dependence have real medical meanings and in the context of this discussion and we shouldn't mix them up. See this very short and to the point lancet medical journal summary, https://www.thelancet.com/journals/lanpsy/article/PIIS2215-0...
>Addiction (synonymous with substance use disorder), as defined by the DSM-5, entails compulsive use, craving, and impaired control over drug taking in addition to physical dependence. The vast majority of patients taking medications such as opioids and benzodiazepines are doing so as prescribed by clinicians, with only 1·5% of people taking benzodiazepine being addicted, for example. Physical dependence is much more common than addiction. Importantly, withdrawal effects occur irrespective of whether these drugs are taken as prescribed or misused.
>Failure to distinguish between addiction and physical dependence can have real-life consequences. People who have difficulty stopping their medications because of withdrawal effects can be accused of addiction or misuse. Misdiagnosis of physical dependence as addiction can also lead to inappropriate management, including referral to 12-step addiction-based detoxification and rehabilitation centres, focusing on psychological aspects of harmful use rather than the physiology of withdrawal.
>It should be made clear that dependence is not the same as addiction. The problems with prescribed drug dependence are not restricted to the small minority who are misusing or addicted to these drugs, but to the wider population who are physically dependent on and might not be able easily to stop their medications because of withdrawal effects. Antidepressants (superkuh note: and caffeine) should be categorised with other drugs that cause withdrawal syndromes as dependence-forming medications, while noting that they do not cause addiction.
The explanation for the headaches is that coffee raises blood pressure short term, and the blood vessels in the brain prepare for the predicted caffeine ingestion, and if it doesn't come there will be a mismatch.
What triggers the blood vessel constriction on the brain? Will avoiding e.g. certain places at certain hours also avoid the preemptive blood vessel constriction and associated headache?