Brain volume in male patients with recent onset schizophrenia with and without cannabis use disorders

Cannabis use in patients with early psychosis is associated with alterations in putamen and thalamic shape

“…A number of subcortical structures have been implicated in cannabis and psychosis as outlined above so we explored this in the main subcortical structures. In line with prior literature, reviewed above (Chye et al, 2019a;Koenders et al, 2015; Smith et al, 2015), we had expected to see regional deflations in the hippocampus in cannabis using participants with psychosis compared to non-cannabis using participants with psychosis as a neurotoxic effect of cannabis; and regional inflations in shape of striatal regions which are involved in addiction circuitry. We also tested whether these differences would be evident between controls with and without a history of cannabis use.…”

“…We limited analysis to the subcortical deep grey matter structures and did not look at cortical thinning, cerebellar volumes, white matter tracts or ventricular enlargement, which may also be impacted by cannabis use. Furthermore the sample size was relatively modest to detect volumetric differences (Koenders et al, 2014) although comparable to previous such studies in shape (Smith et al, 2014;Smith et al, 2015;Solowij et al, 2013). For this reason, we did not try to disentangle genderspecific effects, although there was no significant difference in gender between groups.…”

“…Increased putamen volume has been shown to be associated with methamphetamine use (Andres et al, 2016;Chang et al, 2005;Jan, Lin, Miles, Kydd, & Russell, 2012), with alterations in putamen myeleoarchitecture in those at behavioural risk of addiction (Nord et al, 2019), and increased putamen volumes in probands with stimulant addiction and relatives of those with addictive disorder (Ersche et al, 2012). Two previous studies have examined cannabis use in the context of psychosis: one showed putamen volume increases in cannabis-using compared to non-using PwP (Koenders et al, 2015), whereas the other found neurochemical changes in the left putamen with higher NAA/choline ratio in cannabis-using PwP compared to controls (Malchow et al, 2013). Our study thus extends their findings by demonstrating regional structural change using an alternative analytical strategy and confirming the finding of putamen enlargement in the PwP + C group.…”

“…However, in the early stages of cannabis use in psychosis (≤5 years after illness onset), the morphological characterisation has been less clear. Some studies have shown relative enlargement of hippocampal (Cunha et al, 2013), putamen (Koenders et al, 2015) and cortical regions (Cunha et al, 2013;Schnell, Kleiman, Gouzoulis-Mayfrank, Daumann, & Becker, 2012) and localised increase in the corpus collosum (Malchow et al, 2013) in PwP with cannabis use compared to those who do not use the drug. Others have, however, shown reductions in volume of mediotemporal, striatal, (James et al, 2011), thalamic (Kumra et al, 2012), cerebellar (Cohen et al, 2012;James et al, 2011), and cortical regions (James et al, 2011;Rapp et al, 2013;Szeszko et al, 2007) in PwP with cannabis use compared to PwP who do not use cannabis.…”

Testing associations between cannabis use and subcortical volumes in two large population‐based samples

“…However, another major limitation is sample size. In 21 reports investigating associations between licit or illicit SU and subcortical volumes in one or more regions, the average sample size was 90 . Consequently, larger imaging samples that include measures of cannabis and comorbid SU are required.…”