Home  About us  Contact
 

Rapid Tryptophan Depletion (rapid + tryptophan_depletion)

Distribution by Scientific Domains
Medical Sciences100%

Selected Abstracts

Rapid tryptophan depletion reverses phenelzine-induced suppression of REM sleep

JOURNAL OF SLEEP RESEARCH, Issue 1 2003
Hans-Peter Landolt
SUMMARY Treatment with the monoamine oxidase inhibitor phenelzine completely suppressed rapid eye movement (REM) sleep in five depressed patients. Hypothesizing that increased serotonergic neurotransmission eliminated REM sleep, we administered a tryptophan-free amino acid drink (TFD) known to reduce plasma tryptophan and brain levels of serotonin. The TFD reversed the REM sleep suppression, while the control drink (TFD plus tryptophan) had virtually no effect on sleep. Neither TFD nor control drink affected mood, total sleep time, sleep efficiency or the all-night electroencephalogram power spectra in non-rapid eye movement (NREM) sleep. We report the first non-disruptive, double-blind method for studying human subjects overnight with and without REM sleep. It opens up a novel strategy for investigating the functions of REM sleep, and the roles of serotonin and REM sleep in the regulation of NREM sleep and mood. [source]

Rapid tryptophan depletion as a treatment for acute mania: a double-blind, pilot-controlled study

BIPOLAR DISORDERS, Issue 8 2007
Julia Applebaum
Objectives:, Rapid reduction of up to 80% in plasma tryptophan level can be accomplished by administering an oral tryptophan-free amino acid solution, which induces hepatic protein synthesis and thereby depletes available plasma tryptophan. Rapid tryptophan depletion (RTD) has been shown to induce transient depressive symptoms in patients with remitted major depression. The effect of RTD in acutely manic patients has not been studied. Methods:, We carried out a double-blind, placebo-controlled pilot study of RTD in acutely manic patients. Patients were randomized to the treatment groups. Sodium valproate treatment was started at a dose of 1000 mg/day and continued throughout the 7-day study. On days 1-7, patients received a daily tryptophan-free amino acid drink or a placebo drink. The tryptophan-free amino acid drink contained a mix of amino acids without tryptophan. The placebo drink contained the additives and constituents of the real mixture to provide identical flavor and texture without the amino acids. Ratings were administered at baseline and then repeated on days 3, 5, and 7. All ratings were carried out by an experienced rater who was blind to the group assignment of patients. Results:, A total of 23 patients entered the study and 17 completed the 7-day treatment protocol. The patients who received the amino acid drink showed greater improvement in mania ratings. The differences in Young Mania Rating Scale (YMRS) and Clinical Global Impression (GCI) scores were significant. However, the intolerance rate was high (23%) and the findings in this pilot study are based only on results from those patients who were able to tolerate the drink. Conclusions:, Rapid tryptophan depletion may have an antimanic effect. [source]

Patients with a major depressive episode responding to treatment with repetitive transcranial magnetic stimulation (rTMS) are resistant to the effects of rapid tryptophan depletion

DEPRESSION AND ANXIETY, Issue 8 2007
John P. O'Reardon M.D.
Abstract Repetitive transcranial magnetic stimulation (rTMS) appears to be efficacious in the treatment of major depression based on the results of controlled studies, but little is known about its antidepressant mechanism of action. Mood sensitivity following rapid tryptophan depletion (RTD) has been demonstrated in depressed patients responding to SSRI antidepressants and phototherapy, but not in responders to electroconvulsive therapy (ECT). We sought to study the effects of RTD in patients with major depression responding to a course of treatment with rTMS. Twelve subjects treated successfully with rTMS monotherapy underwent both RTD and sham depletion in a double-blind crossover design. Depressive symptoms were assessed using both a modified Hamilton Depression Rating Scale (HDRS) and Beck Depression Inventory (BDI). The differential change in depression scores across the procedures was compared. No significant difference in mood symptoms was noted between RTD and the sham-depletion procedure on either continuous measures of depression, or in the proportions of subjects that met predefined criteria for a significant degree of mood worsening. Responders to rTMS are resistant to the mood perturbing effects of RTD. This suggests that rTMS does not depend on the central availability of serotonin to exert antidepressant effects in major depression. Depression Anxiety 24:537,544, 2007. © 2006 Wiley-Liss, Inc. [source]