Serotonin and human cognitive performance.
In the past decade, experimental studies involving healthy human volunteers have revealed that manipulations of the central serotonin (5-HT) system can produce quite specific changes in cognitive functioning, independent of overt mood changes. Reduced 5-HT turnover is consistently associated with impaired long-term memory functioning. Low 5-HT function may also impair cognitive flexibility and improve focused attention. On the other hand, stimulation of central 5-HT has repeatedly been found to impair performance in a true vigilance task. Currently, there is little evidence for mirrored cognitive changes due to opposite 5-HT manipulations in healthy volunteers. Given the mounting evidence for a role of 5-HT in human cognition, reduced 5-HT function could be directly linked to cognitive disturbances in certain conditions, such as in depression and Alzheimer's Disease (AD). There is evidence that stimulating (i.e. normalizing) 5-HT activity in depression may have specific beneficial effects on cognition, independent of a general relief of depressive symptoms, but this premise needs to be confirmed by larger-scale clinical studies. Recently, a potential role of 5-HT in the cognitive symptoms in AD has been identified, but there is insufficient data to evaluate the effects of 5-HT stimulation on cognitive symptoms in AD. It is concluded that serotonin is a potential target for pharmacological cognition enhancement, particularly for restoration of impaired cognitive performance due to 5-HT dysfunction. Further differentiation of the role of 5-HT in normal and disturbed cognition and evaluation of the effects of 5-HT manipulations in various populations is required to establish the full potential of 5-HT drugs as cognition enhancers.
Schmitt
J A J
JA
Nestlé Research Center, Nutrition and Health Department, Lausanne, Switzerland. jeroen.schmitt@rdls.nestle.com
Wingen
M
M
Ramaekers
J G
JG
Evers
E A T
EA
Riedel
W J
WJ
D001143:Arousal / Q000502:physiology; D003071:Cognition / Q000502:physiology*; D003863:Depression / Q000503:physiopathology / Q000523:psychology; D006801:Humans; D019636:Neurodegenerative Diseases / Q000503:physiopathology; D011597:Psychomotor Performance / Q000502:physiology*; D012701:Serotonin / Q000502:physiology*
D012701:Serotonin