Aperson whose body can still function properly without the drug, but still craves the drug, even though the "high" is not as intense is

That person is psychologically addicted

A lot of drugs affect our pleasure center of the brain ( usually the drugs that is given if the patient experience a high level of pain, such as Vicodin and Marijuana)

After the treatment is over, sometimes the patients still craves the drug because they missed the recreational effect that come from it