Coffee is stronger than heroin

In a study of the dependence of people on coffee, German scientists
tested 24 people who drink a lot of this invigorating drink (3+ cups
a da by), and 32 people who gety with one cup a day, or do not
drinking coffee. In order to understand how people really relate to
this drink, whether they have a psychological dependence on coffee,
scientists have resorted to an implicit association test (IAT), which is
usually used to assess unconscious biases. During the IAT test, a
person must press computer keys, evaluating objects on the monitor
as "good" or "bad". The difference in reaction time indicates a hidden
relationship to the object shown on the computer screen.
All participants, as well as those with a strong dependence on coffee
and not special lovers of this drink, performed the test two times. The
first time, scientists evaluated how much people craved coffee, and the
second time how they liked it. The team found that people who drank
coffee often, the so-called coffee addicts, showed a higher level of
desire, but on the liking test, the results of the people did not differ
much, they were quite low. The researchers note that a strong urge to
drink coffee without feeling sympathetic is a classic sign of coffee
addiction. “These data confirm that consistent consumption of coffee
generates greater desire, despite a low liking for the drink,” the
authors of the work emphasize. "This discrepancy provides a possible
explanation for the widespread and stable consumption of caffeinated
beverages."