| NCT ID | Title | Phase | Status | Enrollment | Velocity | Design | Start | Completion | Last Updated | Sites | Countries |
|---|---|---|---|---|---|---|---|---|---|---|---|
| NCT00129441 | Gamma-Amino Butyric Acid (GABA)-A Alpha2/3 Study | PHASE2 | COMPLETED | 16 | — | — | Aug 1, 2005 | Jan 1, 2008 | Oct 17, 2011 | 1 | United States |
The N-back task is a sequential-letter memory task for which working memory load is varied, as the respondent must indicate when the current stimulus matches the one from 'n' steps earlier in the sequence. The dependent measure for the N-back task was performance in the 2-back condition, which provides the best index of performance and dorsolateral prefrontal cortex disturbances in subjects with schizophrenia.
The N-back task is a sequential-letter memory task for which working memory load is varied, as the respondent must indicate when the current stimulus matches the one from 'n' steps earlier in the sequence. The dependent measure for the N-back task was performance in the 2-back condition, which provides the best index of performance and dorsolateral prefrontal cortex disturbances in subjects with schizophrenia.
For the AX Continuous Performance Test, subjects are required to maintain an attentional set across a delay interval in order to overcome a prepotent response tendency (target responses are required when an X is presented but only in the context of a preceding A; non-target conditions are AY, BX and BY). The dependent measure was d-prime at the long delay (calculated as AX hits minus BX false alarms, which is particularly sensitive to context processing impairments in individuals with schizophrenia.
The POP task is a cued stimulus-response reversal paradigm that, similar to the AX Continuous Performance Test, requires increases in cognitive control through the maintenance and use of context information to overcome prepotent response tendencies.
The POP task is a cued stimulus-response reversal paradigm that, similar to the AX Continuous Performance Test, requires increases in cognitive control through the maintenance and use of context information to overcome prepotent response tendencies.
| Arm | Type | Description |
|---|---|---|
| Merck L-830982 | EXPERIMENTAL | - |
| Sugar pill | PLACEBO_COMPARATOR | - |
| Name | Type | Description |
|---|---|---|
| Merck L-830982 | DRUG | The initial dose of L-830982 was 3.0 mg twice daily (b.i.d.) the dosage increased to 5.0 mg b.i.d. at the end of week 1 and 8.0 mg b.i.d. at the end of week 2, which was continued for the remaining 2 weeks of the trial. Medications were dispensed weekly in blister packs by the hospital pharmacy. |
| Placebo | DRUG | Medications were dispensed weekly in blister packs by the hospital pharmacy, using the same number of pills as those on active drug. |
Inclusion Criteria: * Male participants * Between the ages of 18 and 50 * Meet diagnostic criteria for schizophrenia or schizoaffective disorder * Are clinically stable for a minimum of 3 months on current dose of medication * Are unemployed (i.e., work less than 20 hours per week at competitive em...