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Author Notes:

Corresponding Author: Mathison Centre for Mental Health Research and Education, University of Calgary, 3280 Hospital Drive NW, Calgary, Alberta T2N 4Z6 Canada. jmadding@ucalgary.ca

Authors’ contributions: LB was responsible for conceptualizing this study, performing analyses and writing the manuscript.

JA, TDC, KSC, BAC, DOP, LJS, THM, MTT, EFW, SWW, were responsible for all aspects of the NAPLS-2 study including study design, obtaining funding, data collection, and all contributed to the writing of the final version of the manuscript.

TDC was responsible for the neuroimaging analysis.

DHM assisted in the conceptualization for this study and assisted in performing the data analysis and writing the manuscript.

CEB was responsible for managing NAPLS-2 at the UCLA Site and contributed to the writing of the final version of the manuscript.

All authors read and approved the final version of the manuscript.

The NIMH had no further role in study design; in the collection, analysis and interpretation of data; in the writing of the report; and in the decision to submit the paper for publication.

All authors declare no conflict of interest.


Research Funding:

This study was supported by the National Institute of Mental Health (grant U01MH081984 to Dr Addington; grants U01 MH081928; P50 MH080272; Commonwealth of Massachusetts SCDMH82101008006 to Dr Seidman; grants R01 MH60720, U01 MH082022 and K24 MH76191 to Dr Cadenhead; grant U01MH081902 to Dr Cannon; P50 MH066286 (Prodromal Core) to Dr Bearden; grant U01MH082004 to Dr Perkins; grant U01MH081988 to Dr Walker; grant U01MH082022 to Dr Woods; and UO1 MH081857-05 grant to Dr Cornblatt.


  • Amygdala
  • Hippocampus
  • Marijuana
  • Magnetic resonance imaging
  • Neuroanatomy
  • Schizophrenia
  • Thalamus

Relation between cannabis use and subcortical volumes in people at clinical high risk of psychosis

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Journal Title:

Psychiatry Research: Neuroimaging


Volume 254


, Pages 3-9

Type of Work:

Article | Post-print: After Peer Review


Among people at genetic risk of schizophrenia, those who use cannabis show smaller thalamic and hippocampal volumes. We evaluated this relationship in people at clinical high risk (CHR) of psychosis. The Alcohol and Drug Use Scale was used to identify 132 CHR cannabis users, the majority of whom were non-dependent cannabis users, 387 CHR non-users, and 204 healthy control non-users, and all participants completed magnetic resonance imaging scans. Volumes of the thalamus, hippocampus and amygdala were extracted with FreeSurfer, and compared across groups. Comparing all CHR participants with healthy control participants revealed no significant differences in volumes of any ROI. However, when comparing CHR users to CHR non-users, a significant ROI × Cannabis group effect emerged: CHR users showed significantly smaller amygdala compared to CHR non-users. However, when limiting analysis to CHR subjects who reported using alcohol at a ‘use without impairment’ severity level, the amygdala effect was non-significant; rather, smaller hippocampal volumes were seen in CHR cannabis users compared to non-users. Controlling statistically for effects of alcohol and tobacco use rendered all results non-significant. These results highlight the importance of controlling for residual confounding effects of other substance use when examining the relationship between cannabis use and neural structure.

Copyright information:

© 2016 Elsevier Ireland Ltd. All rights reserved.

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