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

Mass General Brigham

Status and phase: Completed; Phase 4

Conditions: Schizophrenia

Treatments: Drug: d-cycloserine

Study type: Interventional

Funder types: Other

Identifiers

NCT00455702

2005-P-001040

Details and patient eligibility

About

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.

Full description

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:

1. Assess the effects of a single dose of D-cycloserine 50 mg on cognitive functioning compared to placebo.
2. Assess the effects of repeated weekly dosing of D-cycloserine on cognitive functioning at week 8 compared to placebo.
3. Assess the effects of repeated weekly dosing of D-cycloserine on memory functioning once a week 1 hour after medication administration compared to placebo.
4. 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.
5. Assess effects of weekly D-cycloserine dosing on positive & negative symptoms at week 8 compared to placebo.
6. Assess tolerability and side effects of weekly D-cycloserine compared to placebo.
7. Assess the effects of d-cycloserine dosed weekly for seven weeks on reward responsiveness as measured with the response bias task compared with placebo.
8. Assess the effects of d-cycloserine dosed weekly for seven weeks on measures of functioning.

Enrollment: 38 patients

Sex: All

Ages: 18 to 65 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

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

Exclusion criteria

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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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38 participants in 2 patient groups, including a placebo group

D-cycloserine

Experimental group

Description:

50 mg d-cycloserine

Treatment:

Drug: d-cycloserine

Placebo

Placebo Comparator group

Description:

50 mg placebo

Treatment:

Drug: d-cycloserine