Disorders due to Substance Use: Caffeine

Caffeine is the world’s most used psychoactive drug. Caffeine is found in coffee, tea, soft drinks, chocolate, dietary supplements, and medications. Caffeine acts via adenosine receptor antagonism and indirect dopamine neurotransmission to produce alerting and mood-enhancing effects. Although most people can consume caffeine without adverse health effects, there is considerable variability in individual response to caffeine due to genetic differences, co-occurring health conditions, and tolerance resulting from habitual use. Consumption of excessive caffeine, either acutely or chronically, can result in a range of psychiatric symptoms that may cause functional impairment in otherwise healthy individuals. The ubiquity of caffeine consumption makes diagnosing caffeine-related disorders challenging. This chapter reviews five caffeine-related disorders: caffeine intoxication, caffeine withdrawal, caffeine use disorder, caffeine-induced anxiety disorder, and caffeine-induced sleep disorder. This review also provides information so that clinicians can provide recommendations for caffeine reduction when appropriate for their patients.