Sex differences in the effect of acute tryptophan depletion on declarative episodic memory: a pooled analysis of nine studies.
Acute tryptophan depletion (ATD) studies have shown that serotonin plays a role in learning and memory processes. In this study, we performed a pooled analysis of nine ATD studies in order to examine the nature of the memory-impairing effects of ATD and mediating factors, such as gender, age and vulnerability for disease in which disturbed serotonin was hypothesized to play a role. All studies that were used in this pooled analysis assessed declarative episodic memory using a verbal learning task paradigm. Immediate recall, delayed recall, and delayed recognition scores were examined. A total of 211 participants were included in the analysis. The analysis revealed that ATD impaired not only delayed recall, but also immediate recall. The ATD-induced impairments were larger in females than in males. Furthermore, ATD did not interact with any other serotonergic vulnerability and age. This suggests that the only factor that actually has the properties of a serotonergic vulnerability factor for declarative memory performance is female gender. The findings provide further support for a critical role of serotonin in declarative episodic memory.
Sambeth
Anke
A
Department of Neurocognition, Faculty of Psychology, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands. anke.sambeth@psychology.unimaas.nl
Blokland
Arjan
A
Harmer
Catherine J
CJ
Kilkens
Tessa O C
TO
Nathan
Pradeep J
PJ
Porter
Richard J
RJ
Schmitt
Jeroen A J
JA
Scholtissen
Bart
B
Sobczak
Sjacko
S
Young
Allan H
AH
Riedel
Wim J
WJ
D000293:Adolescent; D000328:Adult; D000339:Affect / Q000502:physiology; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D018592:Cross-Over Studies; D003863:Depression / Q000378:metabolism; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D008875:Middle Aged; D016032:Randomized Controlled Trials as Topic; D012701:Serotonin / Q000502:physiology*; D012737:Sex Factors; D014364:Tryptophan / Q000172:deficiency* / Q000378:metabolism
D012701:Serotonin; D014364:Tryptophan