Table 3.
Cognitive measures.
| Study’s 1st author, year | Creatine group patients (males/females) | Placebo group patients (males/females) | Type of treatment | Cognitive measures | Outcome |
|---|---|---|---|---|---|
| Watanabe et al., 2002 | N = 12 (NR) | N = 12 (NR) | 8 g/d (in 4 doses) for 5 d | Uchida-Kraepelin test (UKT) | The regression coefficient of the creatine group significantly increased from 0.0115 to 0.0055 (p < 0.02, paired t-test), no significant changes in the placebo group (from 0.0078 to 0.0087, p > 0.5) |
| Rae et al., 2003 | Crossover design | Crossover design | 5 g/d for six weeks | Raven’s Advanced Progressive Matrices (RAPMs) | Oral creatine significantly increased intelligence (as measured by RAPMs done under time pressure) compared with placebo (p < 0.0001; repeated-measures ANO VA). No significant effect of treatment order (p = 0.21), although there was a significant interaction with treatment order (p = 0.0004) |
| Wechsler Auditory backward digit span (BDS) task | Oral creatine significantly affected performance on BDS (p < 0.0001), with no effect oi order (p = 0.40) | ||||
| McMorris et al., 2007a | N = 15 (8/7) | N = 17 (8/9) | 5 g creatine 4×/d for 7d | Random number generation | No difference between groups |
| Forward number recall | Creatine group was improved compared to placebo (p < 0.01) | ||||
| Backward number recall | No difference between groups | ||||
| Forward spatial recall | Creatine group was improved compared to placebo (p < 0.05) | ||||
| Backward spatial recall | Creatine group was significantly improved compared to placebo (p < 0.01) | ||||
| Long term memory test | Creatine group was significantly improved compared to placebo (p < 0.01) | ||||
| Rawson et al., 2008 | N = 11 (6/5) | N = 11 (7/4) | 0.03 g/kg per day for 6 weeks | Simple reaction time | No difference between groups |
| Immediate code substitution | No difference between groups | ||||
| Delayed code substitution | No difference between groups | ||||
| Logical reasoning | No difference between groups | ||||
| Mathematical processing | No difference between groups | ||||
| Running memory | No difference between groups | ||||
| Memory recall | No difference between groups | ||||
| Ling et al., 2009 | N = 17 (11/6) | N = 17 (11/6) | 5 g/d for 2 weeks | Memory Scanning | |
| Stimulus number in set-RT | Improvement only for cr. group (p < 0.01) | ||||
| Stimulus number in set-NI | Improvement only for cr. group (p < 0.01) | ||||
| Stimulus number not in set-RT | Improvement only for cr. group (p < 0.01) | ||||
| Stimulus number not in set-NI | Improvement only for cr. group (p < 0.05) | ||||
| Overall mean-RT | Improvement only for cr. group (p < 0.01) | ||||
| Overall NI | Improvement only for cr. group (p < 0.01) | ||||
| Number-Pair Matching | |||||
| Overall RT | Improvement only for cr. group (p < 0.01) | ||||
| Overall NI | Improvement only for cr. group (p < 0.01) | ||||
| Sustained Attention | |||||
| Number of correct responses | No change for any group | ||||
| RT correct responses | Improvements for both groups (ps < 0.05) | ||||
| Number of false positives | No change for any group | ||||
| Number of correct omissions | Improvement only for cr. group (p < 0.01) | ||||
| Number of incorrect omissions | No change for any group | ||||
| Arrow Flankers | |||||
| Overall number of false alarms | Improvement only for cr. group (p < 0.01) | ||||
| Overall RT | Improvement for both cr. group and placebo group (ps < 0.01 and < 0.05) | ||||
| Overall NI | Improvement only for cr. group (p < 0.01) | ||||
| IQ score | Improvement only for cr. group (p < 0.01) | ||||
| Benton and Donohoe, 2011 | N = 61 (0/61) | N = 60 (0/60) | 5 g/d for 5 days | Word list recall | Improvement for vegeterians of cr.group compared to meat eaters of cr.group (p < 0.001). No changes for placebo group |
| RT | No change for any group | ||||
| Vigilance | No change for any group | ||||
| Word fluency | No change for any group |