gray matter atrophy in the temporal pole in regular cannabis users and the degree of atrophy related to the frequency of drug use in the 3 months preceding inclusion in the study. Previous research using ROI analysis did not focus on possible changes in this region. With regard to the two studies using VBM, one (Matochik et al, 2005) found changes only in the medial part of the temporal cortex, maybe due to the small sample studied; the other (Cousijn et al, 2012) failed to find any change in the cerebral cortex. Atrophy of this structure has been found in cocaine users (Albein-Urios et al, 2013) and has been linked to socioemotional and personality problems.
