Sub-chronic Effects of 5-hydroxytryptophan on Mood and Emotional Processing in Healthy Volunteers

NCT01514409 | Completed

• 1 other identifier: 24AQ1
• Study Type: interventional
• Target: 33
• Locations: 1 country
• Sites: 1

Brief Summary

5-hydroxytryptophan (5-HTP) is a nutritional supplement sold in many health food stores, and is taken in order to raise levels of serotonin in the brain. Serotonin is a neurotransmitter that is involved in the regulation of mood. Previous research has assessed the effects of raising serotonin levels using tryptophan (the precursor of 5-HTP) and serotonergic antidepressants on emotional processing in healthy volunteers. However, to date there has been no human trial investigating the effects of 5-HTP on emotional processing in healthy volunteers. Thus, the current study aims to assess the effects of 5-HTP, on emotional processing and mood in healthy volunteers.

Conditions

Mood

Keywords

5-hydroxytryptophan; Mood; Emotional Processing; Emotional Cognition; Nutritional Supplement; Low mood

Outcome Measures

Primary Outcomes (5)

• Beck Depression Inventory-II (BDI-II)

  The BDI-II is a measure used to assess the severity of depressive symptoms. It is comprised of 21 items that are scored on a scale ranging from 0-3, with total scores ranging from 0-63. Scores of over 16 are indicative of depressive symptoms.

  14 days

• Profile of Mood States-Bipolar (POMS-BI)

  The POMS-BI is a measure used to assess subjective mood. It comprises 72 adjectives which describe mood states. Participants indicate how well the adjectives describe how they feel on a four point scale ranging from 0-3. The POMS-BI measures the following six bipolar mood states: composed-anxious, elated-depressed, agreeable-hostile, clearheaded-confused, energetic-tired, and confident-unsure.

  14 days

• Emotional Perception: Facial Expression Recognition Task

  Participants are shown faces displaying five different emotions - happiness, sadness, fear, anger, and disgust. Each facial expression has been morphed between 0% (neutral) to 100% in 25% increments. Four examples of each emotion at each intensity are displayed on a computer screen (84 stimuli presentations in total). Faces are displayed for 500ms aand then replaced with a blank screen. Participants have to indicate what facial expression has been displayed by clicking the corresponding button on-screen with the mouse. Accuracy, reaction times, and misclassifications are measured.

  14 days

• Emotional Categorisation and Memory

  Participants are shown sixty personality characteristics consecutively (30 agreeable, 30 disagreeable)on a computer screen in random order for 500ms each. Participants are asked to judge whether the personality traits are 'likeable' or 'dislikeable'. Classifications and reaction times for correct choices are recorded. Participants are then asked to recall as many personality characteristics as they can in order to assess their incidental memory for positive versus negative material.

  14 days

• Emotional Attention: Attentional Probe Task

  The attentional probe task based on MacLeod, Matthews and Tata's (1986) visual attention paradigm is used to assess participants attention towards positive versus negatively valenced words. Accuracy and reaction time is recorded.

  14 days

Study Arms (2)

5-Hydroxytryptophan

EXPERIMENTAL

Dietary Supplement: 5-Hydroxytryptophan

Placebo

PLACEBO COMPARATOR

Dietary Supplement: Pharmaceutical grade silica

Interventions

5-Hydroxytryptophan DIETARY_SUPPLEMENT

Thirty-three participants were randomly allocated in a double-blind manner to receive either 3x50mg capsules of 5-HTP or placebo (silica) for 14 days. 5-HTP is produced commercially by extraction from the seeds of the African plant griffonia simplicifolia.

5-Hydroxytryptophan

Pharmaceutical grade silica DIETARY_SUPPLEMENT

Pharmaceutical grade silica was utilized as placebo

Placebo

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Male/Female
• Healthy
• Aged 18-65
• Not taking any herbal or prescription medications (excluding contraceptive pill)
• Free from depressive illness or mood disorder for the last 6 months
• Free of physical illness

You may not qualify if:

• Physically ill
• History of medical illness
• Current or previous (6 month) history of psychiatric disorder
• Pregnant/breastfeeding
• Allergy or hypersensitivity to any of the ingredients contained in the investigational product
• Taking any medication (excluding contraceptive pill)

Sponsors & Collaborators

• Northumbria University: lead

Study Sites (1)

Northumbria University

Newcastle upon Tyne, United Kingdom

Location

MeSH Terms

Conditions

Consciousness Disorders

Interventions

5-Hydroxytryptophan

Condition Hierarchy (Ancestors)

Neurobehavioral Manifestations; Neurologic Manifestations; Nervous System Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Neurocognitive Disorders; Mental Disorders

Intervention Hierarchy (Ancestors)

Tryptophan; Amino Acids, Aromatic; Amino Acids, Cyclic; Amino Acids; Amino Acids, Peptides, and Proteins

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 17, 2012
• First Posted: January 23, 2012
• Study Start: May 1, 2011
• Primary Completion: August 1, 2011
• Study Completion: August 1, 2011
• Last Updated: January 23, 2012

Record last verified: 2012-01

Locations

GB (1)