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

This study has been completed.

Sponsor:

Information provided by (Responsible Party):

Northumbria University

ClinicalTrials.gov Identifier:

NCT01514409

First received: January 17, 2012

Last updated: January 20, 2012

Last verified: January 2012

History of Changes

Tracking Information
First Received Date ^ICMJE	January 17, 2012
Last Updated Date	January 20, 2012
Start Date ^ICMJE	May 2011
Primary Completion Date	August 2011 (final data collection date for primary outcome measure)
Current Primary Outcome Measures ^ICMJE (submitted: January 20, 2012)	Beck Depression Inventory-II (BDI-II) [ Time Frame: 14 days ] [ Designated as safety issue: No ] 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. Profile of Mood States-Bipolar (POMS-BI) [ Time Frame: 14 days ] [ Designated as safety issue: No ] 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. Emotional Perception: Facial Expression Recognition Task [ Time Frame: 14 days ] [ Designated as safety issue: No ] 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. Emotional Categorisation and Memory [ Time Frame: 14 days ] [ Designated as safety issue: No ] 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. Emotional Attention: Attentional Probe Task [ Time Frame: 14 days ] [ Designated as safety issue: No ] 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.
Original Primary Outcome Measures ^ICMJE	Same as current
Change History	Complete list of historical versions of study NCT01514409 on ClinicalTrials.gov Archive Site
Current Secondary Outcome Measures ^ICMJE	Not Provided
Original Secondary Outcome Measures ^ICMJE	Not Provided
Current Other Outcome Measures ^ICMJE	Not Provided
Original Other Outcome Measures ^ICMJE	Not Provided

Descriptive Information
Brief Title ^ICMJE	Sub-chronic Effects of 5-hydroxytryptophan on Mood and Emotional Processing in Healthy Volunteers
Official Title ^ICMJE	Sub-chronic Effects of 5-hydroxytryptophan on Mood and Emotional Processing in Healthy Volunteers: A Randomised Trial
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.
Detailed Description	The serotonin precursor 5-HTP is sold as a nutritional supplement and has been used to offset low mood for over 30 years due to its ability to raise levels of neural serotonin. However, evidence for the efficiency of 5-HTP is limited and the mechanism of action of 5-HTP in offsetting low mood has not been well-characterised. The current study assessed the ability of 5-HTP to induce biases for positive emotional material in healthy volunteers, similar to those induced by serotonergic antidepressants and the nutritional supplement tryptophan. The effects of 5-HTP on subjective mood and depressive symptoms were also assessed. Participants were randomised to receive either 150mg of 5-HTP or placebo daily for 14 days. Depressive symptoms and subjective mood were assessed pre- and post-intervention. Emotional processing was assessed on the 15th day using a battery of emotionally valenced cognitive tasks.
Study Type ^ICMJE	Interventional
Study Phase	Not Provided
Study Design ^ICMJE	Allocation: Randomized Endpoint Classification: Efficacy Study Intervention Model: Parallel Assignment Masking: Double Blind (Subject, Investigator, Outcomes Assessor) Primary Purpose: Treatment
Condition ^ICMJE	Mood
Intervention ^ICMJE	Dietary Supplement: 5-Hydroxytryptophan 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. Dietary Supplement: Pharmaceutical grade silica Pharmaceutical grade silica was utilized as placebo
Study Arm (s)	Experimental: 5-Hydroxytryptophan Intervention: Dietary Supplement: 5-Hydroxytryptophan Placebo Comparator: Placebo Intervention: Dietary Supplement: Pharmaceutical grade silica
Publications *	Not Provided
* Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.

Recruitment Information
Recruitment Status ^ICMJE	Completed
Enrollment ^ICMJE	33
Completion Date	August 2011
Primary Completion Date	August 2011 (final data collection date for primary outcome measure)
Eligibility Criteria ^ICMJE	Inclusion Criteria: 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 Exclusion Criteria: 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)
Gender	Both
Ages	18 Years to 65 Years
Accepts Healthy Volunteers	Yes
Contacts ^ICMJE	Contact information is only displayed when the study is recruiting subjects
Location Countries ^ICMJE	United Kingdom

Administrative Information
NCT Number ^ICMJE	NCT01514409
Other Study ID Numbers ^ICMJE	24AQ1
Has Data Monitoring Committee	No
Responsible Party	Northumbria University
Study Sponsor ^ICMJE	Northumbria University
Collaborators ^ICMJE	Not Provided
Investigators ^ICMJE	Not Provided
Information Provided By	Northumbria University
Verification Date	January 2012
^ICMJE Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP

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