The new study found that just a single one-hour session of "reduction-strategy" therapy - a type of cognitive behavioural therapy - helped patients lower their caffeine intake by more than 75 percent. The goal of this type of talk therapy is to help patients understand, recognize and change irrational thoughts that are causing their behavior.

Caffeine-use disorder, though not yet an official mental health diagnosis, is defined by caffeine dependency and an inability to consume less caffeine despite a desire to do so, the researchers explained.

Caffeine is a commonplace central nervous system stimulant drug which occurs in nature as part of the coffee, tea, yerba mate and other plants. It is also an additive in many consumer products, most notably beverages advertised as energy drinks. Caffeine is also added to sodas such as Coca-Cola and Pepsi, where, on the ingredients listing, it is designated as a flavouring agent.

Caffeine's mechanism of action is somewhat different from that of cocaine and the substituted amphetamines. Caffeine blocks adenosine receptors. Adenosine is a by-product of cellular activity, and stimulation of adenosine receptors produces feelings of tiredness and the need to sleep. Caffeine's ability to block these receptors means the levels of the body's natural stimulants, dopamine and norepinephrine, continue at higher levels.