NCT01514409

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

Sub-chronic Effects of 5-hydroxytryptophan on Mood and Emotional Processing in Healthy Volunteers: A Randomised Trial

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 33 (actual)
• Sponsor: Northumbria University · Academic / Other
• Sex: All
• Age: 18 Years – 65 Years
• Healthy volunteers: Accepted

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.

Conditions

• Mood

Interventions

Type	Name	Description
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

Timeline

• Start date: 2011-05-01
• Primary completion: 2011-08-01
• Completion: 2011-08-01
• First posted: 2012-01-23
• Last updated: 2012-01-23

Locations

1 site across 1 country: United Kingdom