Effect of N-acetylcysteine on Brain Glutamate (NAC)

King's College London

Status: Completed

Conditions: Psychosis

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

Study type: Observational

Funder types: Other

Identifiers

NCT02483130

BRCNAC

Details and patient eligibility

About

A double-blind, placebo controlled, crossover study to determine whether a single dose of N-acetylcysteine (a nutritional supplement) can reduce brain glutamate levels in patients with a psychotic disorder. Secondary outcomes are to determine the pattern of alteration in brain perfusion and activity following a single dose of N-acetylcysteine.

Full description

This is a physiological, proof-of-concept study designed to investigate whether a single administration of N-acetylcysteine can reduce brain glutamate levels in people with psychotic disorders.

Previous research suggests that poor response to antipsychotics may be linked to increased levels of glutamate in the brain (Egerton et al., 2012; Demjaha, Egerton et al., 2013). Reducing brain glutamate levels may therefore be therapeutic. This study tests whether it is possible to reduce brain glutamate levels in psychotic disorders.

This is a small pilot study to determine whether a single administration of NAC can reduce brain glutamate levels in psychosis. At the same time, we will also examine the effects of NAC on brain resting perfusion and activity, to gain more information about how NAC may be acting.

This study will recruit participants with a previous diagnosis of a psychotic disorder. There will be three study visits, 1-2 weeks apart. The first visit will involve a physical health check, blood sample and an interview to assess current symptoms and confirm medical history. On the second and third visits participants will have an MRI scan, lasting one hour, after taking capsules containing either 2400mg NAC or placebo.

Enrollment: 20 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Over 18 years of age
• Diagnosis of a psychotic disorder
• Have mental capacity to consent

Exclusion criteria

• Diagnosed drug or alcohol dependency, with the exception of nicotine
• Pregnancy, as determined through a urine pregnancy test
• Presence of any physical health abnormality which may impact on safety to participate in the research, as determined by a study clinician on the basis of the physical health check and the available medical information.
• Presence of electronic or metallic implants contraindicated to MRI scanning at 3 Tesla, or presence of any other contraindication to MRI
• History of asthma
• History of epilepsy or any other seizure
• Under 18 years of age
• Lacking mental capacity to consent
• Current or previous use of NAC
• Currently prescribed clozapine

Trial design

20 participants in 1 patient group

NAC or Placebo

Description:

Participants will receive 2400mg capsules of N-Acetylcysteine or placebo

Treatment:

Dietary Supplement: N-Acetylcysteine

Other: Placebo