Are Tryptophan and 5-Hydroxytryptophan Effective Treatments for Depression? A Meta-Analysis

Shaw, Kelly A.; Turner, Jane; Mar, Chris Del

doi:10.1046/j.1440-1614.2002.01046.x

Cited by 50 publications

(27 citation statements)

References 16 publications

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“…There are several reports that plasma tryptophan is significantly lower in patients with major depression than in normal controls or in patients with only minor symptoms of depression (Coppen et al, 1973;Cowen et al, 1989). Furthermore, administration of tryptophan has been used as an antidepressant (reviewed by Shaw et al, 2002).…”

Section: Factors Affecting 5-hydroxytryptophan Availability For Serotmentioning

confidence: 99%

Serotonin a la carte: Supplementation with the serotonin precursor 5-hydroxytryptophan

Turner

Loftis

Blackwell

2006

Pharmacology & Therapeutics

275

158

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This paper reviews the preclinical and clinical evidence regarding the use of the dietary supplement 5-hydroxytryptophan (5-HTP) for the treatment of depression. In the absence of supplementation with exogenous 5-HTP, the amount of endogenous 5-HTP available for serotonin synthesis depends on the availability of tryptophan and on the activity of various enzymes, especially tryptophan hydroxylase, indoleamine 2,3-dioxygenase, and tryptophan 2,3-dioxygenase (TDO). Factors affecting each of these are reviewed. The amount of 5-HTP reaching the central nervous system (CNS) is affected by the extent to which 5-HTP is converted to serotonin in the periphery. This conversion is controlled by the enzyme amino acid decarboxylase, which, in the periphery, can be blocked by peripheral decarboxylase inhibitors (PDIs) such as carbidopa. Preclinical and clinical evidence for the efficacy of 5-HTP for depression is reviewed, with emphasis on double-blind, placebo-controlled (DB-PC) trials. Safety issues with 5-HTP are also reviewed, with emphasis on eosinophilia myalgia syndrome (EMS) and serotonin syndrome. D

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Section: Factors Affecting 5-hydroxytryptophan Availability For Serotmentioning

confidence: 99%

Serotonin a la carte: Supplementation with the serotonin precursor 5-hydroxytryptophan

Turner

Loftis

Blackwell

2006

Pharmacology & Therapeutics

275

158

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“…It is hypothesized that adjunctive tryptophan may potentiate serotonergic neurotransmission, mediating antidepressant benefits by the process of 'precursor loading'. 85 The recommended dose in clinical practice is 2 to 4 g/day, with a suggested duration of 3 to 4 months. 85,86 A systematic review 69 and 1 RCT 87 have been published since 2009, with no clear evidence to support an adjunctive role for tryptophan to treat MDD (Suppl .…”

Section: What Is Tryptophan? How Effective Is Tryptophan For the Treamentioning

confidence: 99%

Canadian Network for Mood and Anxiety Treatments (CANMAT) 2016 Clinical Guidelines for the Management of Adults with Major Depressive Disorder: Section 5. Complementary and Alternative Medicine Treatments

Ravindran¹,

Balneaves²,

Faulkner³

et al. 2018

FOC

127

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Methods: Using the question-answer format, we conducted a systematic literature search focusing on systematic reviews and meta-analyses. Evidence was graded using CANMAT-defined criteria for level of evidence. Recommendations for lines of treatment were based on the quality of evidence and clinical expert consensus. ''Complementary and Alternative Medicine Treatments'' is the fifth of six sections of the 2016 guidelines. Results: Evidence-informed responses were developed for 12 questions for 2 broad categories of complementary and alternative medicine (CAM) interventions: 1) physical and meditative treatments (light therapy, sleep deprivation, exercise, yoga, and acupuncture) and 2) natural health products (St. John's wort, omega-3 fatty acids; S-adenosyl-L-methionine [SAM-e], dehydroepiandrosterone, folate, Crocus sativus, and others). Recommendations were based on available data on efficacy, tolerability, and safety. Conclusions: For MDD of mild to moderate severity, exercise, light therapy, St. John's wort, omega-3 fatty acids, SAM-e, and yoga are recommended as first-or second-line treatments. Adjunctive exercise and adjunctive St. John's wort are second-line recommendations for moderate to severe MDD. Other physical treatments and natural health products have less evidence

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“…5HTP is recommended as a supplemental treatment for depression and menopausal hot flush (Curcio et al, 2005;Shaw et al, 2002). In humans, the typical 5HTP dosage is 100-300 mg/day or 1-3 mg/kg [reviewed by (Turner et al, 2006)].…”

Section: Therapeutic Elevation Of 5ht Ext By 5ht-promoting Drugsmentioning

confidence: 99%

How Much Serotonin in the CNS is Too Much?

Tao¹,

Ma²

2012

When Things Go Wrong - Diseases and Disorders of the Human Brain

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Are Tryptophan and 5-Hydroxytryptophan Effective Treatments for Depression? A Meta-Analysis

Cited by 50 publications

References 16 publications

Serotonin a la carte: Supplementation with the serotonin precursor 5-hydroxytryptophan

Serotonin a la carte: Supplementation with the serotonin precursor 5-hydroxytryptophan

Canadian Network for Mood and Anxiety Treatments (CANMAT) 2016 Clinical Guidelines for the Management of Adults with Major Depressive Disorder: Section 5. Complementary and Alternative Medicine Treatments

How Much Serotonin in the CNS is Too Much?

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