Once Weekly D-cycloserine for Schizophrenia

2014-07-24 14:11:46 | BioPortfolio


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


In a previous placebo-controlled trial, we demonstrated significant improvement of negative symptoms with once-weekly D-cycloserine treatment. In addition, we found significant improvement of memory consolidation following the first dose; however, the effect on memory consolidation was lost after several weeks. The "practice effect" of weekly measurement of memory consolidation using repeated administration of the Logical Memory Test may have resulted in a "ceiling effect" which would obscure drug/placebo differences. In the current study, we propose to administer the Logical Memory Test at four-week intervals (weeks 1, 4 and 8) to avoid the ceiling effect. We will also add a measurement of negative symptoms at week 4 to better characterize the time course of negative symptom improvement.


1. Assess the effects of a single dose of D-cycloserine 50 mg on memory consolidation as measured by the Logical Memory Test compared to placebo.

2. Assess the persistence of once-weekly D-cycloserine effects on memory consolidation measured at weeks 4 & 8.

3. Assess the effects of repeated weekly dosing of D-cycloserine on performance on a standard cognitive battery at week 8 compared to placebo.

4. Assess effects of weekly D-cycloserine dosing on negative symptoms at weeks 4 & 8 compared to placebo.

5. Assess tolerability and side effects of weekly D-cycloserine compared to placebo.

Study Design

Allocation: Randomized, Control: Placebo Control, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Treatment




D-cycloserine, Placebo


Massachusetts General Hospital
United States




National Institute of Mental Health (NIMH)

Results (where available)

View Results


Published on BioPortfolio: 2014-07-24T14:11:46-0400

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Schizophrenia is a common  serious long-term mental health condition that affects 5 in 1000 in the UK. It causes a range of different psychological symptoms; hallucinations, delusions, muddled thoughts based on the hallucinations or delusions and ch...

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