Both Stimulatory and Inhibitory Effects of Dietary 5-Hydroxytryptophan and Tyrosine are Found on Urinary Excretion of Serotonin and Dopamine in a Large Human Population [Expression of Concern]

This article refers to:

RETRACTED ARTICLE: Both stimulatory and inhibitory effects of dietary 5-hydroxytryptophan and tyrosine are found on urinary excretion of serotonin and dopamine in a large human population

Trachte G, Uncini T, Hinz M. Neuropsychiatr Dis Treat. 2009;5:227–235.

The Editor-in-Chief and Publisher of Neuropsychiatric Disease and Treatment wish to issue an Expression of Concern for the published article.

Concerns have been raised regarding the alleged undisclosed competing interests of some of the authors, and the level of information provided on methodology, study data and process of institutional ethical approval for the published article. Neuropsychiatric Disease and Treatment would like to alert readers of this while our investigation is still ongoing and we will provide an update following the conclusion of our investigation.

The authors have been informed of these concerns and of our investigation.