Abstract

Vulnerability markers for onset of anxiety disorders are scarce. In depression, patients at risk tend to respond with a negative mood to ‘acute tryptophan depletion’ (ATD), while healthy volunteers and current patients do not. The serotonergic system thus provides indications for vulnerability for depression. It is unknown whether ATD reveals vulnerability in anxiety too. This study systematically reviews the effects of ATD on anxiety and assesses whether challenging anxiety modifies the response. PubMed, Embase and PsychInfo were systematically searched up to April 2019 for studies in which (1) healthy volunteers or patients with a (remitted) anxiety disorder underwent ATD and (2) levels of anxiety were reported. In total, 21 studies were included. Studies conducted in healthy volunteers (n = 13), and patients with a remitted (n = 6) or current (panic, social or generalised) anxiety disorder (n = 4). Studies were mostly of poor quality and heterogeneous regarding population, challenge test used and outcome measures. ATD did not consistently affect anxiety in any of the groups. Moreover, a challenge test after ATD (n = 17 studies) did not consistently provoke anxiety in healthy volunteers or remitted patients. A 35% CO2 challenge did consistently increase anxiety in patients with a current panic disorder (PD). To conclude, this systematic review found no clear indications that ATD provokes anxiety in those at risk for anxiety disorders. Hence, unlike in depression, ATD does not indicate vulnerability to develop an anxiety disorder. Because included studies were heterogeneous and mostly of poor quality, there is an urgent need for high quality research in homogeneous samples.

Details

Title
Effects of tryptophan depletion on anxiety, a systematic review
Author
Schopman Simone M E 1   VIAFID ORCID Logo  ; Bosman, Renske C 1   VIAFID ORCID Logo  ; Muntingh Anna D T 1 ; van Balkom Anton J L M 1 ; Batelaan, Neeltje M 1 

 Amsterdam Public Health institute, Amsterdam UMC, Vrije Universiteit, Department of Psychiatry, Amsterdam, The Netherlands (GRID:grid.12380.38) (ISNI:0000 0004 1754 9227); GGZ inGeest Specialized Mental Health Care, Amsterdam, The Netherlands (GRID:grid.420193.d) (ISNI:0000 0004 0546 0540) 
Publication year
2021
Publication date
2021
Publisher
Nature Publishing Group
e-ISSN
21583188
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2488175493
Copyright
© The Author(s) 2021. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.