Behavioral and Cognitive Effects of the N-methyl-D-aspartate Receptor (NMDAR) Co-agonist D-serine in Healthy Humans

The efficacy of compounds having agonistic activity at the glycine site associated with the N-methyl-D-aspartate receptor (NMDAR) is presently assessed in psychiatric disorders. In contrast to NMDAR antagonists, the neuropsychiatric effects of NMDAR agonists in the healthy human organism are not known. The investigators studied neuropsychiatric and neurochemical effects of the NMDAR-glycine site obligatory co-agonist D-serine (DSR) in healthy subjects using a randomized, controlled crossover challenge design including a baseline assessment day and two treatment administration days (DSR and placebo in randomized order). Thirty-five subjects aged 23-29 years participated in the study and received a 2.1g orally administered DSR dose. The main outcome measures were the changes in scores of mood-related Visual Analogue Scale (VAS), Continuous Performance Test - Identical Pairs (CPT-IP), and Rey Auditory Verbal Learning Test (RAVLT).

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Key information

Conditions

Healthy

Age range

18 year–45 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

About this study

The study employed a randomized, double-blind, placebo controlled crossover design according to which, following a baseline assessment session, subjects were tested under two acute treatment conditions on two separate days. Following the baseline assessment day, 16 subjects were randomized, using a computer-generated random number sequence, to receive during test day 1 DSR and 19 to receive placebo. During test day 2, these two groups of subjects were crossed over to receive the alternative experimental treatment. The time intervals between the baseline assessment day, test day 1 and test day 2 were two to three weeks and 1 month respectively, in order to avoid the possibility of any carry-over effects.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

healthy volunteers

Exclusion criteria

history of psychiatric, medical, neurological illness or substance abuse

Treatment and study plan

D-serine

Other

single P.O. administration of D-serine (2.1g)

Other names: DSR

Placebo

Other

single P.O. administration of Placebo

Other names: corn starch

Primary outcomes

Change in Visual Analogue Scale (VAS) of Anxiety - From Baseline to 2 Hours

Time frame: Baseline, 2 hours post intervention

The subject was asked to point on the VAS scale according to his anxiety level. VAS anxiety scale 0 to 10 ( 0 [no anxiety] to 10 [maximum anxiety] ).
Change in Cognitive Function- CPT-IP D-prime Score - From Baseline to 2 Hours

Time frame: Baseline, 2 hours post intervention

The "d-prime score" is a score given to each participant on a scale of 0.0 - 1.0 in which discrimination sensitivity is measured. A score of 0 equates to no sensitivity whereas a score of 1.0 equates to perfect sensitivity.
Change in Rey Auditory Verbal Learning Test RAVLT (Trial 7) - From Baseline to 2 Hours

Time frame: Baseline, 2 hours post intervention

RAVLT measures short term verbal memory, verbal learning, susceptibility to (proactive and retroactive) interference, retention of information after a certain period of time during which other activities are performed and recognition memory. The test consists of a list of 15 common nouns, which are read to the subject in five consecutive trials (trials 1 through 5); each reading is followed by a free-recall task. In trial 6, an interface list of 15 new common nouns is presented, followed by free recall of these new nouns. In trial 7, without additional reading, subjects are again asked to recall the first list. Twenty minutes later, without an additional reading, subjects are asked to recall once more the first list (trial 8). The RAVLT score range from 0-90 correctly recalled words. For trial 7 the score ranges from 0 to 15 correctly recalled words.

Sponsors and collaborators

Lead sponsor

Herzog Hospital

Other

Registry information

Acronym: NMDAR

Important dates

Study start: 2007
Primary completion: 2013
Study completion: 2013
First posted: Jan 31, 2014
Registry last updated: Nov 19, 2014

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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