Caffeine consumption, Sleep and Depressed Youth.

If you are a teenager reading this blog you do not need a professional study to tell you that you like sleep. It is no surprise that with a full on social life (facebook included); staying up late to get assignments done that are due tomorrow; and having to get up early for school that you often do not get the amount of sleep you need to function during the day (Stores, 2001, pg 87). Insert need for caffeine* here. Fact: Lots of people consume caffeine daily.

Studies have found that around 75%-98% of young people will have at least one drink a day that contains caffeine and 31% will drink two or more (Whalen et al., 2008, p 358).


Caffeine can be found in coffee, tea, soft drinks- particularly colas, chocolate, and even in some aspirin products (Buysse, 2005, p39; Barlow & Durand, 2009, p 405). More recently popular amongst young people are highly caffeinated, sugar filled, energy drinks.

However, what the researchers and writers of this study are really interested in is whether or not caffeine has an impact on young people with depression and their sleeping habits.

What the researchers wanted to find out.

The idea behind this study was to see if there is a link between caffeine use, sleep and it’s affects on youth with depression, as not much is currently known (Whalen et al., 2008, p 358). Sleeping difficulties are a common factor of depression, making it very important to understand what effect caffeine may also be playing in the lives of young people with depression.  The researchers asked four key questions.

  1. Do young people with depression use more caffeine in their daily lives than healthy young people?
  2. Do young people with depression say their sleep is poorer than healthy young people?
  3. How does a daily intake of caffeine relate to sleep and affect?
  4. Do sleep and caffeine use change as young people with major depressive disorder (MDD) go through treatment (medication and therapy)?

(Whalen et al., 2008, p359)

How the researchers did it.

30 young people with MDD and 23 healthy youth had to report on “caffeine use, sleep and affect in their natural environment” (Whalen et al., 2008, p 358) over an 8 week period. During that time the youth with MDD received treatment, either medication or therapy or a combination of both (Whalen et al., 2008, p 358). The researchers noted that 63% of the young people with depression also had an anxiety disorder (Whalen et al., 2008, p 360).

In order to be a “healthy youth” in this study, the young people needed to prove they and their close relatives had never had any psychological issues.

Since the amount of sleep you have had and how you feel when you wake up are a few of those tricky things to determine, there was a clear assessment method that the researchers used to make sure the data was not messed up. This included multiple daily phone calls to the young people to ask how they were feeling and how much caffeine that had consumed that day (Whalen et al., 2008, p 361).

What the researchers found.

The answers to their questions

  1. Youth with depression consume more caffeine than healthy youth.
  2. Youth with depression report that it takes longer to fall asleep, more night time awakenings, more difficulty waking up and overall a lower rating of sleep quality, than healthy youth.
  3. There is not a significant connection between daily intake of caffeine and sleep, with the exception of daytime caffeine use and predicting more night time awakenings. However there is a connection between caffeine consumption and predicting the nervousness of youth.
  4. The amount of caffeine the youth with MDD consumed decreased over the course of the treatment, but their sleep did not improve.

(Whalen et al., 2008, pp360-363)


The researchers concluded that while depressed young people drink more caffeinated beverages than healthy young people there seems to be little connection between caffeine and depressed youth’s generally poor sleeping habits. Perhaps poor sleep is simply a symptom of depression. However they still believe that there may be connections between caffeine, depression and anxiety. The researchers acknowledge that more research needs to be done to further understand these connections (Whalen et al., 2008, p365).

What the researchers did not take into account was the types of caffeine being consumed or the exact time of day that is was consumed. It was also a small group of people that they conducted the research on limiting the data they received. These factors could vary the outcome of the research. The researchers made a parallel between caffeine and anxiety in depressed young people, but did not put much emphasis on the fact that 63% of the depressed youth already had anxiety.

What does this mean for you?

If you are having trouble sleeping; getting to sleep, waking up during the night or having trouble getting out of bed in the morning why not try altering your caffeine intake? Other studies have shown that caffeine can delay sleep, shorten the amount of time you are asleep, worsen sleep quality (Carskadon, 2002, p126; Shneerson, 2000, p36) and “because caffeine takes a relatively long time to leave our bodies, sleep can be disturbed if the caffeine is ingested in the hours close to bedtime” (Barlow & Durand, 2009, p 405).

But it’s not all bad news! Not everyone reacts to caffeine the same way. Tolerance levels vary between different people depending on how sensitive they are to caffeine (Wilmhurst, 2009, p 475). “A number of studies have found that people who drink at least two portions of caffeinated beverages a day reported better moods, a better social disposition, and more self confidence and energy” (Weinberg & Bealer, 2001, pg 299). Interestingly two big studies showed “lower rates of suicide among coffee drinkers, strongly suggest that caffeine can significantly ameliorate long-term depression and even make life worth living for some people” (Weinberg & Bealer, 2001, pg 299). So perhaps a cup of coffee or two a day isn’t so bad after all.


Key things to remember

  • Caffeine is not a bad thing (in moderation)
  • Limit your daily intake of caffeine (it may or may not help you sleep better)
  • Excessive amounts of caffeine can have negative side effects
  • If, after reading this, you think you may have depression or a sleep disorder speak to a healthcare professional

* FYI: Caffeine is a drug and is classified as a ‘stimulant’ because it increases activity in the central nervous system (Nairne, (2009) p 200; Wilmhurst, (2009), p 447). It is commonly referred to as the ‘gentle stimulant’ because it is seen as the least harmful of addictive drugs (Barlow & Durand, (2009), p 405). Other drugs classified as stimulants including nicotine, amphetamines and cocaine (Nairne, (2009), p 200). “As with other stimulants, regular caffeine use can result in tolerance and dependence on the drug” (Barlow & Durand, (2009), p 406).


Barlow, D. H., Durand, V.M. (2009). Abnormal Psychology. Belmont, CA, USA: Wadsworth Cengage Learning.

Buysse, D. J. (ed). (2005). Sleep Disorders and Psychiatry. Washington, DC: American Psychiatric Publishing.

Carskadon, M. A. (2002). Adolescent Sleep Patterns. Cambridge, UK: Cambridge University Press.

Nairne, J. S. (2009). Psychology 5th edition. Canada: Thomson Wadsworth.

Shneerson, J. M. (2000). Handbook of Sleep Medicine. Cambridge, UK: Blackwell Science.

Stores, G. (2001). A Clinical Guide to Sleep Disorders in Children and Adolescents. Cambridge, UK: Cambridge University Press.

Weinberg, B. A., Bealer, B. K. (2001). The World of Caffeine; The science and culture of the worlds most popular drug. New York, USA: Routledge.

Whalen, D. L., Silk, J. S., Semel, M., Forbes, E. E., Ryan, N. D., Axelson, D. A., Birmaher, B. & Dahl, R. E. (2008). Caffeine consumption, sleep, and affect in the natural environments of depressed youth and healthy controls. Journal of Paediatric Psychology, 33 (4), 358-367.

Wilmhurst, L. (2009). Abnormal Child Psychology; A Developmental Perspective. New York, USA: Routledge.