The issue of possible dependence on caffeine has been debated for many years. In humans, the widely recognised behavioural stimulant and mildly reinforcing properties of caffeine are likely to be responsible for the maintenance of caffeine consumption22. A 2014 review concludes that there is insufficient evidence to reach firm conclusions in this area and further work is required23.
People may drink coffee from habit; the possible reinforcing effects of coffee may not be due to the caffeine per se, but linked to the pleasurable aroma and taste of coffee, as well as the social environment that usually accompanies coffee consumption24.
Learn more about caffeine’s effect on the brain by watching a video here.
Studies of blood flow measurements suggest that caffeine did not activate the brain circuit of dependence in humans, but activated regions involved in attention, vigilance, and anxiety25. These results confirm pre-clinical data reporting no involvement of the circuit of dependence in the physiological effects of caffeine25. In other words, based on the results of studies that used brain mapping technology, caffeine does not fulfil the criteria to be described as a drug of dependence.
The American Psychiatric Association has indicated that more research is needed to determine the clinical significance of Caffeine Use Disorder before the diagnosis may be recognised in the DSM as a clinical disorder26.
Withdrawal
Among the symptoms linked to dependence is withdrawal. In 2013, the American Psychiatric Association released an updated edition of its Diagnostic and Statistical Manual of Mental Disorders, the DSM-5, which provides standardised criteria for the classification of mental disorders. For the first time since its launch in 1952, it addresses ‘caffeine withdrawal’. In the manual, caffeine withdrawal is defined as a syndrome resulting from abrupt cessation or reduction in caffeine, following prolonged daily use26.
Caffeine withdrawal has been documented in some people, with common symptoms including headache, fatigue, difficulty concentrating, and dysphoric mood. Low consumption of caffeine have been shown to suppress these symptoms22.
