|This article needs additional citations for verification. (December 2008)|
The most common naturally caffeinated beverages are coffee and tea, which in one form or another (usually served hot, but sometimes iced) feature in most world cultures. Other drinks are artificially caffeinated as part of their production process. These include certain soft drinks (primarily cola drinks), and also energy drinks designed as a stimulant, and to perpetuate activity at times when the user might ordinarily be asleep.
The consumption of caffeinated drinks is often intended entirely or partly for the physical and mental effects of caffeine. Examples include the consumption of tea or coffee with breakfast in many westernized societies, in order to 'wake oneself up', or the deliberate consumption of energy drinks by students wishing to study through the night, or revellers seeking to maintain an alert attitude during social recreation. Caffeine can cause a physical dependence, if consumed in excessive amounts. The need for caffeine can be identified when individuals feel headaches, fatigue and muscle pain 24 hours after their last energy drink. 
Many caffeinated drinks also have decaffeinated counterparts, for those who enjoy the taste, but wish to limit their caffeine intake because of its physical effects, or due to religious or medical perceptions of the drug and its effects.
In recent years, some alcoholic beverage companies have begun to manufacture caffeinated alcoholic beverages. The manufacturing of such beverages has been met with much controversy. 
- David, Iulia Gabriela; Bizgan, Ana-Maria Cristina; Buleandra, Mihaela; Popa, Dana Elena; Moldovan, Zenovia; Bandea, Irinel Adriana (April 2015). "Rapid determination of total polyphenolic content in tea samples based on caffeic acid voltammetric behaviour on a disposable graphite electrode.". Food Chemistry 173: 1059–1065.
- Gimba, Casimir Emmanuel; Abechi, Stephen Eyije; Abbas, Nurudeen Sulaiman (2014). "Evaluation of caffeine, aspartame and sugar contents in energy drinks.". Journal of Chemical and Pharmaceutical Research 6 (8): 39-43.
- Rockett, Ian R.H.; Putnam, Sandra L. (February 2002). "CAFFEINE "ADDICTION" IN HIGH SCHOOL YOUTH: EVIDENCE OF AN ADVERSE HEALTH RELATIONSHIP.". Addiction Research and Theory 10 (1): 31-42.
- "Caffeine (and its effects)". Health Central. Remedy Health Media. Retrieved 5 November 2014.
- Bempong DK, Houghton PJ, Steadman K (1993). "The xanthine content of guarana and its preparations". Int. J. Pharmacog. 31 (3): 175–81. doi:10.3109/13880209309082937. ISSN 0925-1618.
- Benson, Sarah; Verster, Joris C.; Alford, Chris; Scholey, Andrew (November 2014). "Effects of mixing alcohol with caffeinated beverages on subjective intoxication: A systematic review and meta-analysis.". Neuroscience & Biobehavioral Reviews 47: 16-21.