Prolonged tryptophan depletion and family history: Effects on mood and memory

Praag, H. M. van; Klaassen, Tim; Riedel, Wolfgang W.; Honig, Adriaan

doi:10.1016/s0006-3223(97)87326-x

Cited by 2 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These results were presented elsewhere (van Praag et al 1997) and can be considered a replication of the findings by Benkelfat et al (1994). There was no effect of FH on cognitive performance and since there appeared to be no association between cognitive and mood responses to T9, it seems that these effects are not dependent on one another.…”

Section: Discussionsupporting

confidence: 88%

Tryptophan depletion in normal volunteers produces selective impairment in memory consolidation

et al. 1999

View full text Add to dashboard Cite

Serotonin (5-hydroxytryptamine; 5-HT) circuits may play a role in cognitive performance, particularly in learning and memory. Cognitive impairment is often seen in depressed patients, in whom 5-HT turnover in the brain is thought to be lowered. A possible human pharmacological model to study the involvement of the serotonergic system in cognitive impairment is to reduce central 5-HT synthesis through L-tryptophan depletion in healthy subjects. In this study, the cognitive effects of tryptophan depletion were assessed and whether genetically or developmentally determined vulnerability factors were predictive of the cognitive impairment induced by tryptophan depletion. Sixteen healthy volunteers with a positive family history of depression and 11 without were given 100 g of an amino acid mixture with or without tryptophan, according to a double-blind, cross-over design. Tryptophan depletion specifically impaired long-term memory performance in all subjects: delayed recall performance, recognition sensitivity, and recognition reaction times were significantly impaired after tryptophan depletion relative to placebo. Short-term memory and perceptual and psychomotor functions were unchanged. There were no differences between groups with a positive and a negative family history for depression. On the basis of these results, it is concluded that tryptophan depletion specifically impairs long-term memory formation, presumably as a result of an acute decrease in 5-HT turnover in the brain.

show abstract

Section: Discussionsupporting

confidence: 88%

Tryptophan depletion in normal volunteers produces selective impairment in memory consolidation

et al. 1999

View full text Add to dashboard Cite

show abstract

“…The results of that study are reported elsewhere (Van Praag et al 1997). All subjects gave their written informed consent prior to their inclusion and were paid for their participation in the study.…”

Section: Methodsmentioning

confidence: 99%

Specificity of the tryptophan depletion method

Klaassen

Riedel²,

Deutz

et al. 1999

Psychopharmacology

View full text Add to dashboard Cite

Thirteen healthy subjects were subjected to tryptophan (TRP) depletion, lysine (LYS) depletion, and a placebo condition in a double blind cross-over study. The aim of the study was to test the specificity of psychological effects induced by TRP depletion. Subjects ingested a 100 g amino acid mixture with or without TRP or LYS. Six hours later, plasma TRP levels had decreased by 77% in the TRP depletion test and LYS levels by 51% in the LYS depletion condition. After 6 h of TRP depletion, subjects reported significantly more tiredness and lowering of mood, compared to subjects in the placebo group, and memory performance declined. After 6 h of LYS depletion, no significant differences in mood and memory compared to placebo were found. We conclude that the effects of TRP depletion on mood and memory are specific for the depletion of TRP and are not caused by the depletion of an amino acid per se. This supports the hypothesis that TRP depletion affects brain serotonin metabolism and not only brain protein metabolism in general.

show abstract

Prolonged tryptophan depletion and family history: Effects on mood and memory

Cited by 2 publications

References 0 publications

Tryptophan depletion in normal volunteers produces selective impairment in memory consolidation

Tryptophan depletion in normal volunteers produces selective impairment in memory consolidation

Specificity of the tryptophan depletion method

Contact Info

Product

Resources

About