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01-03 fMRI in schizophrenia and cannabis users

Published online by Cambridge University Press:  11 July 2016

M Cohen,
V Carr,
PB Ward,
T Ehlkes,
P Johnston,
R Thienel and
U Schall
M Cohen
Affiliation:
Hunter New England Mental HealthCentre for Mental Health Studies, The University of NewcastleNeuroscience Institute of Schizophrenia and Allied Disorders (NISAD), New South Wales, Australia
V Carr
Affiliation:
Hunter New England Mental HealthCentre for Mental Health Studies, The University of NewcastleNeuroscience Institute of Schizophrenia and Allied Disorders (NISAD), New South Wales, Australia
PB Ward
Affiliation:
The Hunter Neuroscience & Brain and Mental Health Research Program, Hunter Medical Research Institute (HMRI)Neuroscience Institute of Schizophrenia and Allied Disorders (NISAD), New South Wales, Australia
T Ehlkes
Affiliation:
Neuroscience Institute of Schizophrenia and Allied Disorders (NISAD), New South Wales, Australia
P Johnston
Affiliation:
Centre for Mental Health Studies, The University of NewcastleNeuroscience Institute of Schizophrenia and Allied Disorders (NISAD), New South Wales, Australia
R Thienel
Affiliation:
Neuroscience Institute of Schizophrenia and Allied Disorders (NISAD), New South Wales, Australia
U Schall
Affiliation:
Hunter New England Mental HealthCentre for Mental Health Studies, The University of NewcastleNeuroscience Institute of Schizophrenia and Allied Disorders (NISAD), New South Wales, Australia
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Abstract

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Information

Type
Abstracts from ‘Brainwaves’— The Australasian Society for Psychiatric Research Annual Meeting 2006, 6–8 December, Sydney, Australia
Information
Acta Neuropsychiatrica , Volume 18 , Issue 6 , December 2006, pp. 314
Copyright
Copyright © 2006 Blackwell Munksgaard

Background:

The cerebral activation changes associated with the overlapping cognitive features of cannabis use and schizophrenia have not been systematically studied. The Tower of London Task (TOL) was used to assess functional brain activation in these two groups and in comorbid first-episode schizophrenia and cannabis users.

Methods:

Event-related functional magnetic resonance imaging measured cerebral activation during the TOL task in 12 patients with first-episode schizophrenia, 17 recently abstinent long-term cannabis users, 7 recently abstinent cannabis using patients with schizophrenia and 17 healthy subjects. A two-stage random-effects analysis was used to model the BOLD response to assess cortical activation as a function of increasing task difficulty and to assess for the main effect of each diagnosis.

Results:

We found prefrontal activation defi cits in patients with schizophrenia that overlapped with cannabis users. A statistical trend in the comorbid subjects for reduced BOLD activation in the left superior parietal lobule and prefrontal cortices was observed. The diagnosis of schizophrenia largely accounted for the prefrontal deficit, while a history of heavy cannabis use associated with increased BOLD activation in the visual cortex.

Conclusions:

There were common deficits in activation of the dorsolateral prefrontal cortex to the most difficult tasks. Ancillary brain regions were recruited, possibly to subserve the demands of complex TOL tasks. The combination of cannabis use and schizophrenia may exert a synergistic effect on altering frontal lobe recruitment during high-demand cognitive tasks.