Effects of Dietary Caffeine on Mood

The article "The Effects of dietary caffeine on mood when rested and sleep restricted" by Jack E. James and M. Elizabeth Gregg, reveals some interesting insights regarding the role the drug caffeine on the human behaviour termed as 'mood'. The rationale for this research is to study the link between caffeine and human emotions. Its purpose was to determine whether dietary caffeine has a legitimate effect on the mood and can it calm the troughs and peeks of mood arising from non-caffeine cause, mainly sleep restriction.

To conduct this research a placebo controlled study was conducted in which both male and female participants took part. A total of 48 individuals, 18 males and 38 females, participated in the study. The participants were given caffeine in smaller portion through morning till early evening. They were then told to abstain from the drug for the night so as to track its effect over a period of 12-16 hours. The dosage ranged from 2-7 cups of coffee per day containing approximately 180-680 mg of caffeine. The experiment consisted of identical looking capsules of caffeine and placebo which is maize starch. The participants were given their quota of capsules and were refrained from taking any caffeinated beverage. Weekly laboratory tests were conducted on all the 48 individuals taking part in the study. The volunteers were sleep deprived on the selected days, allowing them to sleep only 40% of their body sleep routine.

During the experiment the mood was assessed through the computerized profile of mood states (POMS). Along with the mood scales, participants went through weekly guessing of what they thought they had in the capsules taken. The results were gathered using the three-way mixed model ANOVA technique.  The results indicated major effect of caffeine on the mood. The caffeine dose coupled with the sleep deprivation factor aggravated the mood resulting in emotions like anger, hostility, restlessness etc. The results indicated links between gender, sleep pattern and caffeine. The effect of gender is visible in the vigour activity, with males showing more activity than females. Thus, the study proved the hypothesis that "POMS is sensitive to quite subtle caffeine effects, including those that arise by way of interaction with sleep variables." (James, & Gregg, 2004)

This study has proved to be an interesting one. I am a regular user of caffeine in the form of tea and coffee. This research does give me a logical reason to label my mood when I have not had the desired amount of caffeine and/ or not slept the normal body sleep hours. Therefore, one should not have a habit of over dosing caffeine as it affects your mood in adverse manner when deprived of it. This article is good for the caffeine consuming market segment and provides valuable insight to the effects of this drug.