The 2002 paper “Does 5-HT restrain panic? A tryptophan depletion study in panic disorder patients recovered on paroxetine” by Bell and colleagues – reprinted in this issue of the Journal – reports on a study undertaken in the halcyon days of David Nutt’s Psychopharmacology Unit at the University of Bristol, England. In this invited commentary authors of the original work discuss the impact of this paper on the field of acute tryptophan depletion research (especially in the field of clinical anxiety disorders) and the development of disorder-specific anxiogenic provocations over the past decade.
ArgyropoulosSVHoodSDAdroverM. (2004) Tryptophan depletion reverses the therapeutic effect of selective serotonin reuptake inhibitors in social anxiety disorder. Biol Psychiatry56: 503–509.
2.
BadawyAADoughertyDM (2015) Standardization of formulations for the acute amino acid depletion and loading tests. J Psychopharmacol29: 363–371.
3.
BaileyJEDawsonGRDourishCT. (2011) Validating the inhalation of 7.5% CO(2) in healthy volunteers as a human experimental medicine: a model of generalized anxiety disorder (GAD). J Psychopharmacol25: 1192–1198.
4.
BellCForshallSAdroverM. (2002) Does 5-HT restrain panic? A tryptophan depletion study in panic disorder patients recovered on paroxetine. J Psychopharmacol16: 5–14.
5.
BellCHoodSPotokarJ. (2011) Rapid tryptophan depletion following cognitive behavioural therapy for panic disorder. Psychopharmacology213: 593–602.
6.
BooijLvan derDWBenkelfatC. (2002) Predictors of mood response to acute tryptophan depletion. A reanalysis. Neuropsychopharmacology27: 852–861.
ColasantiAEsquivelGdenBE. (2011) Effects of tryptophan depletion and tryptophan loading on the affective response to high-dose CO2 challenge in healthy volunteers. Psychopharmacology215: 739–748.
9.
CorchsFNuttDJHinceDA. (2015) Evidence for serotonin function as a neurochemical difference between fear and anxiety disorders in humans?J Psychopharmacol29: 1061–1069.
10.
CorchsFNuttDJHoodS. (2009) Serotonin and sensitivity to trauma-related exposure in selective serotonin reuptake inhibitors-recovered posttraumatic stress disorder. Biol Psychiatry66: 17–24.
11.
DaviesSJHoodSDArgyropoulosSV. (2006) Depleting serotonin enhances both cardiovascular and psychological stress reactivity in recovered patients with anxiety disorders. J Clin Psychopharmacol26: 414–418.
12.
DaviesSJHoodSDChristmasD. (2008) Psychiatric disorders and cardiovascular disease. Anxiety, depression and hypertension. In: SherL (ed) Psychological Factors and Cardiovascular Disorders: The Role of Psychiatric Pathology and Maladaptive Personality Features. New York: Nova Science Publishers, pp.69–96.
13.
DeakinJFGraeffFG (1991) 5-HT and mechanisms of defence. J Psychopharmacol5: 305–315.
14.
DelgadoPLCharneyDSPriceLH. (1989) Neuroendocrine and behavioral effects of dietary tryptophan restriction in healthy subjects. Life Sci45: 2323–2332.
15.
HoodSHinceDDaviesS. (2010) Effects of acute tryptophan depletion in serotonin reuptake inhibitor-remitted patients with generalized anxiety disorder. Psychopharmacology208: 223–232.
16.
HoodSO’NeilGHulseG (2009a) The role of flumazenil in the treatment of benzodiazepine dependence: Physiological and psychological profiles. J Psychopharmacol23: 401–409.
HoodSD (2015) Latest guidelines for the management of the anxiety disorders – a report from The International Anxiety Disorders Society Conference, Melbourne 2014. Australas Psychiatry23: 388–391.
19.
HoodSDBellCJNuttDJ (2005) Acute tryptophan depletion. Part I: rationale and methodology. Aust N Z J Psychiatry39: 558–564.
20.
HoodSDDaviesSJNuttDJ (2009b) Cardiac slowing and acute tryptophan depletion: A comment on the paper by van der Veen et al. Psychopharmacology203: 831–833; author reply 835–836.
21.
HoodSDHinceDARobinsonH. (2006) Serotonin regulation of the human stress response. Psychoneuroendocrinology31: 1087–1097.
22.
HoodSDNormanAHinceDA. (2014) Benzodiazepine dependence and its treatment with low dose flumazenil. Br J Clin Pharmacol77: 285–294.
23.
HulseGO’NeilGMorrisN. (2013) Withdrawal and psychological sequelae, and patient satisfaction associated with subcutaneous flumazenil infusion for the management of benzodiazepine withdrawal: A case series. J Psychopharmacol27: 222–227.
24.
ISTRY (2016) The International Society for Tryptophan Research. Available at: http://www.istry.org/.
25.
LiebenCKBloklandAWesterinkB. (2004) Acute tryptophan and serotonin depletion using an optimized tryptophan-free protein-carbohydrate mixture in the adult rat. Neurochem Int44: 9–16.
26.
LoprestiALHoodSDDrummondPD (2012) Multiple antidepressant potential modes of action of curcumin: A review of its anti-inflammatory, monoaminergic, antioxidant, immune-modulating and neuroprotective effects. J Psychopharmacol26: 1512–1524.
27.
NeumeisterAHuXZLuckenbaughDA. (2006) Differential effects of 5-HTTLPR genotypes on the behavioral and neural responses to tryptophan depletion in patients with major depression and controls. Arch Gen Psychiatry63: 978–986.
28.
NuttDDemyttenaereKJankaZ. (2007) The other face of depression, reduced positive affect: The role of catecholamines in causation and cure. J Psychopharmacol21: 461–471.
29.
NuttDJGluePLawsonC. (1990) Flumazenil provocation of panic attacks. Evidence for altered benzodiazepine receptor sensitivity in panic disorder. Arch Gen Psychiatry47: 917–925.
30.
SanchezCLVan SwearingenAEArrantAE. (2015) Simplified dietary acute tryptophan depletion: Effects of a novel amino acid mixture on the neurochemistry of C57BL/6J mice. Food Nutr Res59: 27424.
31.
SarrisJLoganACAkbaralyTN. (2015) Nutritional medicine as mainstream in psychiatry. Lancet Psychiatry2: 271–274.
32.
ShufflebothamJHoodSHendryJ. (2006) Acute tryptophan depletion alters gastrointestinal and anxiety symptoms in irritable bowel syndrome. Am J Gastroenterol101: 2582–2587.
33.
SmithKAFairburnCGCowenPJ (1997) Relapse of depression after rapid depletion of tryptophan. Lancet349: 915–919.
34.
SpielbergerCDGrouchRLLusheneRVaggPRJacobsGA (1983) Manual for the State-Trait Anxiety Inventory. Palo Alto, CA: Consulting Psychologists’ Press.
35.
SobczakSSchruersK (2014) Can formulation affect tryptophan depletion results? Hints from studies in experimental panic. J Psychopharmacol28: 486–490.
36.
YoungSNSmithSEPihlRO. (1985) Tryptophan depletion causes a rapid lowering of mood in normal males. Psychopharmacology87: 173–177.
37.
ZepfFDHoodSGuilleminGJ. (2015) Food and your mood: Nutritional psychiatry. Lancet Psychiatry2: e19.