Skip to main content
OpenTrials
Completed

NCT Number: NCT00455702

Effects of Weekly Dosing of D-cycloserine on Cognitive Function in Individuals With Schizophrenia

The study aims to assess the effects of single dose and repeated weekly dosing of 50mg d-cycloserine versus placebo on cognitive and memory functioning in schizophrenia patients. The study will also examine the effects of 50mg d-cycloserine on positive symptoms and negative symptoms, as well as assess tolerability and side-effects.

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Schizophrenia Mental Disorders Schizophrenia Spectrum and Other Psychotic Disorders

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

Primary location

Massachusetts General Hospital

Boston, Massachusetts, 02114, United States

About this study

This is a ten-week, parallel-group, placebo-controlled trial examining the cognitive effects at weeks 1, 2, 3. 4, 5, 6, 7, 8 & 10 of once-weekly oral D-cycloserine 50 mg added to a stable dose of antipsychotic for 8 weeks in 60 adult outpatients with schizophrenia.

Specific aims:

  • Assess the effects of a single dose of D-cycloserine 50 mg on cognitive functioning compared to placebo.
  • Assess the effects of repeated weekly dosing of D-cycloserine on cognitive functioning at week 8 compared to placebo.
  • Assess the effects of repeated weekly dosing of D-cycloserine on memory functioning once a week 1 hour after medication administration compared to placebo.
  • Assess the persistence of learned information in a no-treatment follow-up assessment at Week 10 in the D-cycloserine group compared to the placebo group.
  • Assess effects of weekly D-cycloserine dosing on positive & negative symptoms at week 8 compared to placebo.
  • Assess tolerability and side effects of weekly D-cycloserine compared to placebo.
  • Assess the effects of d-cycloserine dosed weekly for seven weeks on reward responsiveness as measured with the response bias task compared with placebo.
  • Assess the effects of d-cycloserine dosed weekly for seven weeks on measures of functioning.

Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

  • Male or female
  • Age 18-65 years
  • Diagnosis of schizophrenia or schizoaffective disorder, depressed type
  • Stable dose of antipsychotic for at least 4 weeks.
  • Able to provide informed consent
  • Able to complete a cognitive battery

Exclusion criteria

  • Current treatment with clozapine
  • Dementia
  • Seizure disorder
  • Unstable medical illness
  • Active substance abuse
  • Pregnancy, nursing, or unwilling to use appropriate birth control measures during participation if female and fertile.

Treatment and study plan

D-cycloserine

Drug

50mg dose d-cycloserine v placebo

Primary outcomes

  1. Main Outcome Measure: The Change From Baseline to Week 8 on the SANS

    Time frame: Baseline score vs. Week 8

    The change from baseline to week 8 on the scale for the assessment of negative symptoms (SANS) total score. Total SANS scores range from 0-100. The SANS is comprised of 5 subscores: Affective Flattening or Blunting (score range 0-35), Alogia (score range 0-20), Avolition-Apathy (score range 0-15), Anhedonia-Asociality (score range 0-20), and Attention (0-10). For each scale, the higher the score the more prominent the negative symptoms were. The total score was computed by adding all the subscale total scores. To compute change in scores, week 8 scores were subtracted from baseline scores, resulting in a change score. Higher values equals greater improvement (i.e. week 8 score was lower than baseline score).

Secondary outcomes

  1. Treatment Effects on the Positive Syndrome Subscale of the PANSS

    Time frame: Baseline score vs. Week 8 score

    The change from baseline to week 8 on the positive symptom sub-scale of the Positive and Negative Syndrome Scale (PANSS). Total PANSS positive symptom sub-scale scores range from 7-49. The PANSS positive symptom sub-scale is comprised of 7 items rated on a scale of 1-7: delusions, conceptual disorganization, hallucinatory behavior, excitement, grandiosity, suspiciousness/persecution, and hostility. A score of one on each item 1 absent, 2 is minimal, 3 is mild, 4 is moderate, 5 is moderately severe, 6 is severe, and 7 is extreme. The total score was computed by adding all the items on the sub-scale together. To compute change in scores, week 8 scores were subtracted from baseline scores, resulting in a change score. Higher values equals greater improvement (i.e. week 8 score was lower than baseline score).

Sponsors and collaborators

Lead sponsor

Massachusetts General Hospital

Other

Registry information

Official study title

Effects of Weekly Dosing of D-cycloserine on Cognitive Function in Individuals

Important dates

Study start
2004
Primary completion
2007
Study completion
2007
First posted
Apr 4, 2007
Registry last updated
Aug 7, 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.

Related clinical trials

Published trials that share one or more normalized conditions with this study.