A Pilot Trial of Acute N-Acetylcysteine Effects on Working Memory and Other Cognitive Functions in Schizophrenia (NAC)

Yale University

Status: Completed

Conditions: Schizophrenia

Treatments: Drug: Placebo; Dietary Supplement: N-Acetylcysteine

Study type: Interventional

Funder types: Other

Identifiers

NCT01232790

0904005039

M131976 (Other Grant/Funding Number)

Details and patient eligibility

About

The purpose of this study is to evaluate the effects of the amino acid supplement N-Acetylcysteine versus placebo on working memory and other cognitive functions in persons with a diagnosis of schizophrenia.

Full description

Working memory impairment in Schizophrenia is produced by deficiencies of feedback inhibition of glutamate release, due to low cysteine-glutamate antiporter activity. Because of this mechanism, we are interested in whether acute administration of N-Acetylcysteine will improve performance of patients with schizophrenia on a battery of cognitive tasks utilized to test working memory and other cognitive domains, versus placebo. This pilot study will utilize a randomized, double blind, placebo controlled, crossover design.

Enrollment: 28 patients

Sex: All

Ages: 18 to 60 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Subjects will be between 18-60
• Meet Diagnostic and Statistical Manual-IV (DSM) criteria for schizophrenia
• Be on a stable dose of antipsychotic medication for at least 1 month
• Be deemed clinically stable for 3 months by the regular clinical staff

Exclusion criteria

• Current substance or alcohol abuse
• Pregnancy
• Clozapine treatment
• Known sensitivity to sulphur containing compounds
• Previous diagnosis of mental retardation
• Nitroglycerin use
• Asthma diagnosis, verified and treated by a primary care doctor
• Use of any other medication that may interact with the study medication

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Double Blind

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28 participants in 2 patient groups, including a placebo group

Group A: Intervention/Placebo

Experimental group

Description:

Group A first receives the commercially available sustained release form of N-acetylcysteine, then the matching placebo capsules both administered at 1200mg twice a day for 3 full days, along with 1200mg once on the evening prior to and once on the morning following the 3 days (8 total doses over 5 days).

Treatment:

Dietary Supplement: N-Acetylcysteine

Group B: Placebo/Intervention

Placebo Comparator group

Description:

Group B first receives the placebo and then receives a commercially available sustained release form of N-Acetylcysteine. In each arm, the capsules are both administered at 1200mg twice a day for 3 full days, along with 1200mg once on the evening prior to and once on the morning following the 3 days (8 total doses over 5 days).

Treatment:

Drug: Placebo