Longitudinal study of hippocampal volumes in heavy cannabis users

L. Koenders*, V. Lorenzetti, L. De Haan, C. Suo, W. A.M. Vingerhoets, W. Van Den Brink, R. W. Wiers, C. J. Meijer, M. W.J. MacHielsen, A. E. Goudriaan, D. J. Veltman, M. Yücel, J. Cousijn

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

34 Citations (Scopus)
19 Downloads (Pure)

Abstract

Background: Cannabis exposure, particularly heavy cannabis use, has been associated with neuroanatomical alterations in regions rich with cannabinoid receptors such as the hippocampus in some but not in other (mainly cross-sectional) studies. However, it remains unclear whether continued heavy cannabis use alters hippocampal volume, and whether an earlier age of onset and/or a higher dosage exacerbate these changes. Methods: Twenty heavy cannabis users (mean age 21 years, range 18-24 years) and 23 matched non-cannabis using healthy controls were submitted to a comprehensive psychological assessment and magnetic resonance imaging scan at baseline and at follow-up (average of 39 months post-baseline; standard deviation=2.4). Cannabis users started smoking around 16 years and smoked on average five days per week. A novel aspect of the current study is that hippocampal volume estimates were obtained from manual tracing the hippocampus on T1-weighted anatomical magnetic resonance imaging scans, using a previously validated protocol. Results: Compared to controls, cannabis users did not show hippocampal volume alterations at either baseline or follow-up. Hippocampal volumes increased over time in both cannabis users and controls, following similar trajectories of increase. Cannabis dose and age of onset of cannabis use did not affect hippocampal volumes. Conclusions: Continued heavy cannabis use did not affect hippocampal neuroanatomical changes in early adulthood. This contrasts with prior evidence on alterations in this region in samples of older adult cannabis users. In young adults using cannabis at this level, cannabis use may not be heavy enough to affect hippocampal neuroanatomy.

Original languageEnglish
Pages (from-to)1027-1034
Number of pages8
JournalJournal of Psychopharmacology
Volume31
Issue number8
DOIs
Publication statusPublished - 1 Aug 2017

Bibliographical note

Funding:
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study is supported through funding received from the Academic Medical Center of the University of Amsterdam and the Netherlands Organization for Scientific research – Health Research and Development, ZonMW grant #31180002 awarded to AE Goudriaan and W van den Brink and grant #31160007 awarded to L de Haan. Additional funding was obtained from Vici grant #453.008.001 awarded to RW Wiers by the Dutch Organization for Scientific Research (NWO) and from the Amsterdam Brain Imaging Center (BIC) for MRI scans. M Yucel was supported by a National Health and Medical Research Council Fellowship (#1117188) and the David Winston Turner Endowment Fund.

Publisher Copyright:
© The Author(s) 2017.

Fingerprint

Dive into the research topics of 'Longitudinal study of hippocampal volumes in heavy cannabis users'. Together they form a unique fingerprint.

Cite this