Effects of oral 5-hydroxytryptophan on a standardized planning task: insight into possible dopamine/serotonin interactions in the forebrain
Article first published online: 22 APR 2013
Copyright © 2013 John Wiley & Sons, Ltd.
Human Psychopharmacology: Clinical and Experimental
Volume 28, Issue 3, pages 270–273, May 2013
How to Cite
Gendle, M. H., Young, E. L. and Romano, A. C. (2013), Effects of oral 5-hydroxytryptophan on a standardized planning task: insight into possible dopamine/serotonin interactions in the forebrain. Hum. Psychopharmacol. Clin. Exp., 28: 270–273. doi: 10.1002/hup.2314
- Issue published online: 24 MAY 2013
- Article first published online: 22 APR 2013
- Manuscript Accepted: 9 MAR 2013
- Manuscript Received: 27 AUG 2012
- 5-hydroxytryptophan (5-HTP);
- serotonin (5-HT);
- executive function
Several studies have suggested that exogenous administration of the serotonin precursor 5-hydroxytryptophan (5-HTP) can result in the ectopic production of serotonin in dopaminergic neurons and a concomitant reduction in dopamine release. This study tested this hypothesis using the Tower of London (TOL), a test of planning and executive control that is sensitive to changes in forebrain dopamine activity, but insensitive to alterations in serotonin.
A sample of 68 undergraduates participated, and each received either three 50-mg 5-HTP capsules or placebos, and completed the TOL following a set absorption period.
5-HTP significantly lengthened the average time needed to complete each of the 10 trials of the TOL. 5-HTP did not affect accuracy on this task.
Oral exogenous 5-HTP disrupts dopaminergic function in the human forebrain. Copyright © 2013 John Wiley & Sons, Ltd.