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Adjunctive Treatment for Decreasing Symptoms of Schizophrenia

Cognitive and Negative Symptoms in Schizophrenia Trial (CONSIST)

Status
Completed
Phases
Phase 2Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT00222235
Enrollment
240
Registered
2005-09-22
Start date
2000-01-31
Completion date
2004-06-30
Last updated
2019-08-20

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Schizoaffective Disorder, Schizophrenia

Keywords

schizophrenia, schizoaffective disorder, negative symptoms, cognitive impairments

Brief summary

This study will determine the effectiveness of treatment with glycine or d-cycloserine in addition to a normal antipsychotic regimen in improving negative symptoms and cognitive impairments in patients with schizophrenia.

Detailed description

A double-blind, placebo controlled clinical trial to examine whether adjunctive treatment with glycine or d-cycloserine, compared to placebo, will improve negative symptoms and cognitive impairments in patients with schizophrenia who remain on their normal antipsychotic regimen. Multicenter, randomized, double-blinded placebo controlled parallel-groups clinical trial designed to test the hypothesis that interventions (glycine or d-cycloserine) intended to increase glutamatergic activity by action at the NMDA receptor will reduce persistant negative symptoms and cognitive impairments of patients with schizophrenia or schizoaffective disorder. After an initial screening phase to establish clinical stability and eligibility, patients were assigned to one of three adjunctive treatments (placebo, d-cycloserine or glycine)for 16 weeks of double-blind treatment. Patients remained on a stable dose of antipsychotic therapy (other than clozapine) throughout the study.

Interventions

DRUGd-cycloserine
DRUGglycine
DRUGplacebo

Sponsors

National Institute of Mental Health (NIMH)
CollaboratorNIH
The Zucker Hillside Hospital
CollaboratorOTHER
Nathan Kline Institute for Psychiatric Research
CollaboratorOTHER
University of California, Los Angeles
CollaboratorOTHER
Sarah Herzog Hospital
CollaboratorUNKNOWN
University of Maryland, College Park
CollaboratorOTHER
University of Maryland, Baltimore
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE

Eligibility

Sex/Gender
ALL
Age
18 Years to 54 Years
Healthy volunteers
No

Inclusion criteria

* diagnosis of schizophrenia or schizoaffective disorder * stable, enduring negative symptoms above a certain level (SANS \>19) * clinically stable, with psychotic symptoms measured on BPRS below 19, anxiety/depression on BPRS below 15 * extrapyramidal symptoms measured on SAS below 9 * on stable antipsychotic regimen (not including clozapine)

Exclusion criteria

* alcohol or substance dependence within last six months * alcohol or substance abuse within last month * organic brain disorder * medical condition whose pathology or treatment could alter the presentation or treatment of schizophrenia, including active tuberculosis or tuberculosis treatment, kidney stones, and uncontrolled diabetes mellitus * Female participants could not be pregnant and were required to be using a documented method of contraception.

Design outcomes

Primary

MeasureTime frame
changes from baseline in negative symptoms measured on SANS at 4,8,12 and 16 weeks.
change from baseline on neurocognitive battery measured at 16 weeks.

Secondary

MeasureTime frame
change in psychotic and depressive symptoms measured at 4,8,12, and 16 weeks.
changes in extrapyramidal side effects at 4,8,12 and 16 weeks.

Countries

Israel, United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026