title: Energy drinks: psychological effects and impact on well-being and quality of life-a literature review.
abstract: OBJECTIVE
  The market and degree of consumption of energy drinks have exponentially expanded while studies that assess their psychological effects and impact on quality of life remain in the early stages, albeit on the rise. This review aims to examine the literature for evidence of the psychological effects of energy drinks and their impact on the sense of well-being and quality of life.
  
  
  METHODS
  Studies were identified through Pubmed, Medline, and PsycINFO searches from the dates of 1990 to 2011, published in English, using the keywords energy or tonic drinks, psychological effects, caffeine and cognitive functions, mood, sleep, quality of life, well-being, and mental illness. Three authors agreed independently on including 41 studies that met specific selection criteria.
  
  
  RESULTS
  The literature reveals that people most commonly consume energy drinks to promote wakefulness, to increase energy, and to enhance the experience of alcohol intoxication. A number of studies reveal that individuals who consume energy drinks with alcohol were more inclined to be involved in risk-taking behaviors. There was also excessive daytime sleepiness the day following energy drink consumption. Contrary to expectations, the impact of energy drinks on quality of life and well-being was equivocal.
  
  
  CONCLUSIONS
  Energy drinks have mixed psychological and well-being effects. There is a need to investigate the different contexts in which energy drinks are consumed and the impact on mental health, especially in the psychiatrically ill.
authors.affiliation: Cedars-Sinai Medical Center, Department of Psychiatry and Behavioral Neurosciences, Los Angeles, California, USA. Waguih.IsHak@cshs.org
authors.forename: Waguih William
authors.initials: WW
authors.lastname: Ishak
authors.forename: Chio
authors.initials: C
authors.lastname: Ugochukwu
authors.forename: Kara
authors.initials: K
authors.lastname: Bagot
authors.forename: David
authors.initials: D
authors.lastname: Khalili
authors.forename: Christine
authors.initials: C
authors.lastname: Zaky