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Safety and Effectiveness of D-Serine in Schizophrenia

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified October 2008 by National Institute of Mental Health (NIMH).
Recruitment status was:  Active, not recruiting
Information provided by:
National Institute of Mental Health (NIMH) Identifier:
First received: May 2, 2006
Last updated: October 27, 2008
Last verified: October 2008
This study will determine whether increasing D-serine within the body will improve negative symptoms and cognitive impairments in people with schizophrenia.

Condition Intervention Phase
Drug: D-serine
Phase 2

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: PK/PD Study of Escalating Dose D-Serine as Adjunctive Treatment in Schizophrenia

Resource links provided by NLM:

Further study details as provided by National Institute of Mental Health (NIMH):

Primary Outcome Measures:
  • Renal safety measures (serum, UA) [ Time Frame: Measured at Week 4 ]

Secondary Outcome Measures:
  • Positive and Negative Symptoms Scale (PANSS) [ Time Frame: Measured at Week 4 ]
  • Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) Battery [ Time Frame: Measured at Week 4 ]
  • Clinical Global Impression (CGI) [ Time Frame: Measured at Week 4 ]

Estimated Enrollment: 20
Study Start Date: March 2006
Estimated Study Completion Date: June 2008
Estimated Primary Completion Date: June 2008 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: A
Participants will receive treatment with D-serine
Drug: D-serine
D-serine at following dose levels: 30 mg/kg, 60 mg/kg, and 120 mg/kg. PK/PD studies done at day 1. Medication will be administered as powder dissolved in liquid given in two divided doses daily for 4 weeks.

Detailed Description:

Schizophrenia is a life-long brain disorder affecting approximately 1 percent of Americans each year. Schizophrenia can be extremely disabling, causing people to hear voices, experience paranoia or hallucinations, believe that others are controlling their thoughts, and even fail at maintaining a job or caring for themselves. Current medications help to relieve most of these symptoms, but not all. Some people with schizophrenia still suffer from negative symptoms, such as difficulty with talking, expressing emotions, and motivation; they may also suffer from cognitive impairments, such as decreased concentration and memory loss. D-serine, an amino acid found within the body, activates brain cell receptors that appear to play a role in learning and memory. This study will determine whether adding a D-serine solution to a stable antipsychotic medication regimen will decrease negative symptoms in people with schizophrenia.

Participants in this open-label study will remain on their regular medication regimen for at least 2 weeks. During this time and before starting treatment, participants will be interviewed about their emotional problems, marital status, education, family background, employment history, and any drug or alcohol problems. Participants will also undergo a physical exam, an electrocardiogram (EKG), vital sign measurements, psychological tests, cognitive tasks, and an electroencephalogram (EEG). Participants will then begin 4 weeks of treatment with D-serine. In addition to participants' regular medication regimen, they will drink a D-serine powder mixed with water twice daily. Every 2 weeks, participants will undergo a physical exam and an interview about any changes in symptoms or emotional problems that they may be experiencing. Blood and urine samples will be taken throughout the study. After 4 weeks, participants will undergo an EKG, EEG, and the same psychological tests and cognitive tasks completed prior to treatment. A follow-up visit will occur 2 weeks post-treatment to monitor any changes in negative symptoms.


Ages Eligible for Study:   18 Years to 60 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Structured Clinical Interview for DSM-III-R diagnosis of schizophrenia or schizoaffective disorder
  • PANSS 3 factor negative symptom inclusion score greater than 20 prior to study entry
  • PANSS total score between 60 and 110
  • Simpson-Angus Scale total score of 12 or less
  • Calgary Depression Inventory total score of 10 and suicide score less than 2
  • No change in Clinical Global Impressions (CGI) Scale score prior to study entry
  • Chlorpromazine (CPZ) equivalent of 1500 or less
  • Willing to use an effective form of birth control throughout the study if sexually active

Exclusion Criteria:

  • High extrapyramidal symptom (EPS) levels
  • Began, discontinued, or adjusted psychotropic medication within 2 weeks of study entry
  • Taking investigational medication within 2 weeks of study entry
  • Contraindication to study medication
  • Serious or unstable medical illness
  • Pregnant or breastfeeding
  • Alcohol or drug abuse within 6 months of study entry
  • Diagnosed with neurodegenerative disease or a seizure disorder
  • History of a kidney impairment
  • Currently taking clozapine
  • Currently taking more than two antipsychotic medications
  • Currently taking stimulants or cholinesterase inhibitors
  Contacts and Locations
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Please refer to this study by its identifier: NCT00322023

United States, Connecticut
Yale University School of Medicine
New Haven, Connecticut, United States, 06512
United States, New York
The Zucker Hillside Hospital
Glen Oaks, New York, United States, 11004
The Nathan S. Kline Institute for Psychiatric Research
Orangeburg, New York, United States, 10962
Sponsors and Collaborators
National Institute of Mental Health (NIMH)
Principal Investigator: Daniel C. Javitt, MD, PhD Nathan Kline Institute
  More Information

Responsible Party: Daniel Javitt, Nathan Kline Institute Identifier: NCT00322023     History of Changes
Other Study ID Numbers: U01MH074356 ( US NIH Grant/Contract Award Number )
Study First Received: May 2, 2006
Last Updated: October 27, 2008

Keywords provided by National Institute of Mental Health (NIMH):
Negative symptoms

Additional relevant MeSH terms:
Schizophrenia Spectrum and Other Psychotic Disorders
Mental Disorders processed this record on April 24, 2017