Abnormal developmental of hippocampal subfields and amygdalar subnuclei volumes in young adults with heavy cannabis use: A three-year longitudinal study.
Xueyi Zhang, Zhengju Chen, Benjamin Becker, Tong Shan, Taolin Chen, Qiyong Gong
Progress in neuro-psychopharmacology & biological psychiatry January 10, 2025 DOI: 10.1016/j.pnpbp.2024.111156 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Longitudinal observational study Peer reviewed |
|---|---|
| Sample size | 42 |
| Population | Young adults with heavy cannabis use disorder and matched non-cannabis-using healthy volunteers |
| Duration | 3-year follow-up |
| Measures | Cannabis Use Disorder Identification Test (CUDIT), T1-structural magnetic resonance imaging (MRI) |
| Topics | Addiction Cannabis |
| Keywords | Amygdala Cannabis use Longitudinal analysis Memory formation Psychoradiology Volume of subregion Hippocampus |
| Key findings | At baseline, young adults with heavy cannabis use disorder had significantly larger volumes in several hippocampal and amygdala subregions than controls, but these differences were attenuated at the 3-year follow-up. Longitudinal analysis revealed accelerated volumetric decreases in the cannabis group, with significant decreases in the right parasubiculum, subiculum, and CA4-dentate gyrus, and similar trends in several amygdala nuclei. The authors suggest that long-term heavy cannabis use impacts the maturational process of these regions, especially subregions with high cannabinoid type 1 receptor concentrations and involvement in adult neurogenesis. |
Abstract
Differences in the volumes of the hippocampus and amygdala have consistently been observed between young adults with heavy cannabis use relative to their non-using counterparts. However, it remains unclear whether the subfields of these functionally and structurally heterogenous regions exhibit similar patterns of change in young adults with long-term heavy cannabis use disorder (CUD). This study aims to investigate the effects of long-term heavy cannabis use in young adults on the subregional structures of the hippocampus and amygdala, as well as their longitudinal alterations. The study sample comprised 20 young adults with heavy cannabis use and 22 matched non-cannabis using healthy volunteers. All participants completed the Cannabis Use Disorder Identification Test (CUDIT) and underwent two T1-structural magnetic resonance imaging (MRI) scans, one at baseline and another at follow-up 3 years later. The amygdala, hippocampus, and their subregions were segmented on T1-weighted anatomical MRI scans, using a previously validated procedure. At baseline, young adults with heavy CUD exhibited significantly larger volumes in several hippocampal (bilateral presubiculum, subiculum, Cornu Ammonis (CA) regions CA1, CA2-CA3, and right CA4-Dentate Gyrus (DG)) and amygdala (bilateral paralaminar nuclei, right medial nucleus, and right lateral nucleus) subregions compared to healthy controls, but these differences were attenuated at follow-up. Longitudinal analysis revealed an accelerated volumetric decrease in these subregions in young adults with heavy CUD relative to controls. Particularly, compared to healthy controls, significant accelerated volume decreases were observed in the right hippocampal subfields of the parasubiculum, subiculum, and CA4-DG. In the amygdala, similar trends of accelerated volumetric decreases were observed in the left central nucleus, right paralaminar nucleus, right basal nucleus, and right accessory basal nucleus. The current findings suggest that long-term heavy cannabis use impacts maturational process of the amygdala and hippocampus, especially in subregions with high concentrations of cannabinoid type 1 receptors (CB1Rs) and involvement in adult neurogenesis.