Caffeine - fueling or harming creative writers?

Many of you probably find it hard to get doing without a morning cup of coffee or tea (or three!)  This is normal enough, an even less surprising when you consider that creative types are usually night owls.

What is caffeine?

Caffeine is the world's most popular psychoactive drug.  It is a stimulant which can affect alertness - and therefore performance on a range of tasks.  It is found in coffee, tea, soft drinks, in pill form, and in medicines such as cold remedies.

Coffee and books - a classic combination?
Image by christian.senger

Positive effects

Caffeine can make us think faster and focus for longer.  Research has shown that even a small dose of caffeine, such as that in a glass of coke, can increase alertness with no measurable adverse effects (Lieberman et al., 1987). In a study on university students, Smith et al. (1994) found that caffeine improved performance on semantic memory, logical reasoning, and memory tasks.

Negative effects

Caffeine is a drug, and can have side effects. It increases heart rate and therefore blood pressure, and can be addictive.  There are anecdotal reports of overdose following excessive use, and at extreme levels it can be fatal.  Like other drugs, regular use tends to lead to users becoming resistant to its effects.

Although the research is largely positive, cognitive tasks in the laboratory tend to be fairly simplistic tasks, and don't present a full picture of heavy caffeine use on the real world.  There are probably large individual differences - for example, St Claire et al. (2010) found that  coffee helps women cope with stressful meetings, whereas men got worse!

Context

Many of us turn to caffeine when we are especially busy and stressed. In research with soldiers, Lieberman et al. (2002) studied the effect of caffeine on individuals who were stressed and sleep deprived. The researchers found that caffeine mitigated the effects of the stressors and sleep loss.  In contrast, caffeine may have a detrimental effect if you already highly alert and stimulated, due to the Yerkes-Dodson law.

How important is caffeine in your writing or creative context?  Do you see it as just a habit or part of your routine, or would you be unable to perform at your best without it?  Is there a point where it starts to have an adverse effect?

References

Lieberman, H.R., Tharion, W.J., Shukitt-Hale, B., Speckman, K.L. and Tulley, R. (2002). Effects of caffeine, sleep loss, and stress on cognitive performance and mood during U.S. Navy SEAL training. Psychopharmacology, 164(3), 250-261.
Lieberman, H.R., Wurtman, R.J., , G. G. Emde, C. Roberts and I. L. G. Coviella (1987). The effects of low doses of caffeine on human performance and mood. Psychopharmacology, 92(3), 308-312
Smith, A.P., Kendrick, A., Maben, A. and Salmon, J. (1994). Effects of breakfast and caffeine on cognitive performance, mood and cardiovascular functioning. Appetite, 22(1), 39-55.
St. Claire, L., Hayward, R., and Rogers, P. (2010). Interactive Effects of Caffeine Consumption and Stressful Circumstances on Components of Stress: Caffeine Makes Men Less, But Women More Effective as Partners Under Stress. Journal of Applied Social Psychology, 40(12), 3106-3129