Centre for Youth Mental Health - Research Publications

Permanent URI for this collection

http://hdl.handle.net/11343/250

Filters

2004 - 2009 3
Reset filters

Settings
Statistics
Citations
Author: Berk, Michael × End date: 2009 × Start date: 2002 × Type: Journal Article ×

Search Results

Now showing 1 - 3 of 3
  • Item
    Thumbnail Image
    Glutathione precursor, N-acetyl-cysteine, improves mismatch negativity in schizophrenia patients
    Lavoie, S ; Murray, MM ; Deppen, P ; Knyazeva, MG ; Berk, M ; Boulat, O ; Bovet, P ; Bush, AI ; Conus, P ; Copolov, D ; Fornari, E ; Meuli, R ; Solida, A ; Vianin, P ; Cuenod, M ; Buclin, T ; Do, KQ (NATURE PUBLISHING GROUP, 2008-08)
    In schizophrenia patients, glutathione dysregulation at the gene, protein and functional levels, leads to N-methyl-D-aspartate (NMDA) receptor hypofunction. These patients also exhibit deficits in auditory sensory processing that manifests as impaired mismatch negativity (MMN), which is an auditory evoked potential (AEP) component related to NMDA receptor function. N-acetyl-cysteine (NAC), a glutathione precursor, was administered to patients to determine whether increased levels of brain glutathione would improve MMN and by extension NMDA function. A randomized, double-blind, cross-over protocol was conducted, entailing the administration of NAC (2 g/day) for 60 days and then placebo for another 60 days (or vice versa). 128-channel AEPs were recorded during a frequency oddball discrimination task at protocol onset, at the point of cross-over, and at the end of the study. At the onset of the protocol, the MMN of patients was significantly impaired compared to sex- and age- matched healthy controls (p=0.003), without any evidence of concomitant P300 component deficits. Treatment with NAC significantly improved MMN generation compared with placebo (p=0.025) without any measurable effects on the P300 component. MMN improvement was observed in the absence of robust changes in assessments of clinical severity, though the latter was observed in a larger and more prolonged clinical study. This pattern suggests that MMN enhancement may precede changes to indices of clinical severity, highlighting the possible utility AEPs as a biomarker of treatment efficacy. The improvement of this functional marker may indicate an important pathway towards new therapeutic strategies that target glutathione dysregulation in schizophrenia.
  • Item
  • Item
    Thumbnail Image
    A pilot randomized, double-blind, placebo-controlled study of granisetron in the treatment of sexual dysfunction in women associated with antidepressant use
    Jespersen, S ; Berk, M ; Van Wyk, C ; Dean, O ; Dodd, S ; Szabo, CP ; Maud, C (LIPPINCOTT WILLIAMS & WILKINS, 2004-05)
    A pilot study was conducted to evaluate the usefulness of granisetron for the treatment of antidepressant induced sexual dysfunction in women. Twelve women with antidepressant induced sexual dysfunction (AISD) were assigned granisetron (n=5) or placebo (n=7) in a 14-day randomized, double-blind, placebo-controlled study. One participant in the granisetron group did not complete the study. Participants were assessed at baseline, day 7 and day 14 using the Feiger Sexual Function and Satisfaction Questionnaire and the Arizona Sexual Experience Scale. No statistical differences were measured at baseline or at endpoint between the granisetron or placebo group. This study did not produce evidence supporting the usefulness of granisetron in AISD.