Clinical trial NCT01514409: Sub-chronic Effects of 5-hydroxytryptophan on Mood and Emotional Processing in Healthy Volunteers
Official title: Sub-chronic Effects of 5-hydroxytryptophan on Mood and Emotional Processing in Healthy Volunteers: A Randomised Trial
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Mood
Keywords: 5-hydroxytryptophan
Mood
Emotional Processing
Emotional Cognition
Nutritional Supplement
Low mood
Lead sponsor: Northumbria University
Sponsor class: OTHER
First posted: 2012-01-23
Enrollment: 33
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

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.

Eligibility criteria: 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)

Primary outcomes:
measure: Beck Depression Inventory-II (BDI-II)
timeFrame: 14 days
measure: Profile of Mood States-Bipolar (POMS-BI)
timeFrame: 14 days
measure: Emotional Perception: Facial Expression Recognition Task
timeFrame: 14 days
measure: Emotional Categorisation and Memory
timeFrame: 14 days
measure: Emotional Attention: Attentional Probe Task
timeFrame: 14 days
Secondary outcomes:
Other outcomes:
Locations:
city: Newcastle Upon Tyne
country: United Kingdom
facility: Northumbria University
Study officials:
References: