Welcome Introduction Methods Procedure Results discussion email: jivas@anselm.edu Return to Senior Theses Psychology Homepage

Caffeine Withdrawal in Relation to Mood and Performance by: Jennifer Ivas Welcome Thank you for visiting my site. This study is a caffeine withdrawal study. A little background on caffeine: •Caffeine Increases –energy, work, confidence, friendliness, alertness •Caffeine Decreases Fatigue, boredom, Drowsiness Return to top Introduction Previous studies •Schuh and Griffiths (1997) –Caffeine withdrawal study –Used POMS –Concluded that when withdrawing from caffeine there were increased feelings of being worn out, peeved, grouchy, fatigued and exhausted. –Caffeine withdrawal is negative & unpleasant •Kenemans, Wieleman, Zeegers, Verbaten (1999) –Caffeine and Cognitive performance –Hypothesized caffeine would increase speed and rate of detection –Used Stroop test –Results found caffeine decreased reaction time –Therefore withdrawal will increase reaction time •Mitchell and Redman (1992) –Caffeine and Academic performance –Measured short-term memory, mental arithmetic, reading comprehension, serial search, and verbal reasoning –Results show caffeine improved performance on all mental speed related tasks Return to top Methods Participants •1st Sample •38 participants •0-200 ml of caffeine •average intake = 58 ml •2nd Sample •14 participants •0-430 ml of caffeine •average intake = 131 ml Material •POMS (Profile of Mood States Questionnaire) •Stroop •Tapping •CPT •Diet Diary •Craving Questionnaire Return to top Procedure •1st sample –Instructions –Consent –Food diary –POMS –Return 48 hours later –POMS –Craving Questionnaire –Debriefing •2nd Sample –Instructions –Consent –Food diary –POMS –Stroop –Tapping –CPT –Return in 48 hours –POMS –Stroop –Tapping –CPT –Craving Questionnaire –Debriefing Return to top Results The profile of mood states questionnaire was used to assess self-reported mood in the first sample, which was comprised of the general psychology population. Paired samples t-tests (p=.05) were used to analyze all measures of self-reported mood. The tests found mood states of depression, anger, friendliness, and fatigue to be significant. There was no significant change for vigor. In the second sample, which comprised mostly of self-reported high caffeine users, mood and psychomotor performance was examined. In this sample, the same mood questionnaire was given and results were significant for vigor and friendliness (P<.05). There was no significant change in depression, anger, and fatigue. The psychomotor performance task results are also measured. The first test examined is the Stroop test. A paired samples T-test was conducted and there was significance for time (P<.05), but not for the number correct. There was a significant decrease in tapping from baseline to withdrawal. The continuous performance task showed significance in the errors of omission and time. There was no significance for the errors of commission or number correct. Return to top Discussion •1st Sample –Withdrawal significantly increased Depression, Anger, Fatigue –Withdrawal significantly decreased Friendliness –This supports previous evidence •2nd Sample –Only significant decreases in vigor and friendliness •Reasons –Sample size –Midterm week •Stroop –Time was significantly slower at withdrawal –Supports research that caffeine withdrawal increases reaction time •Tapping –Decreased from baseline to withdrawal •CPT –Time significantly changed –Errors of omission changed (not pressing 6,4 when they did appear) •Academic Concentration –Did not change significantly –Should have tested at baseline and withdrawal Return to top