The Use of Acute Tryptophan Depletion in Children and Adolescents

The neurotransmitter serotonin (5-HT) plays an important role in many neuropsychiatric disorders, in particular affective disorders, eating disorders and disorders related to problems in processing emotions. Different methods have been applied in previous studies on adults to investigate central nervous serotonergic neurotransmission. Acute tryptophan depletion (ATD) is a neurodietary method to reduce central nervous serotonin synthesis in humans for a short period by decreasing the availability of the amino acid tryptophan, TRP, the physiological precursor to 5-HT. Uptake of endogenous TRP into the central nervous system is decreased by a reduced transport of TRP over the blood–brain barrier as TRP competes with other amino acids administered to the subjects within an amino acid beverage lacking TRP after an overnight fast. According to previous studies, frequent side effects of using ATD in adults are vomiting and nausea, thus limiting its use. Here, we present a modified ATD protocol that was adapted for use in children and adolescents, with the administration of an amino acid beverage adapted to the body weight of the subjects. Underlying principles of this ATD modification termed Moja-De and first research findings based on this ATD formulation will be presented and discussed.