In relation to gray matter volume reduction in regions linked to affective and emotional processes described so far (the insula and the orbitofrontal cortex), we also show structural variations in the temporal pole (TP). The TP shares cytoarchitectural and functional characteristics with the orbitofrontal cortex (Kling and Steklis, 1976) and receives projections from the insula. The volume reduction in these regions observed in our population supports the idea of a joint role of these structures in regular cannabis use. Evidence exists about the role of the temporal pole (TP) in coupling emotions and highly processed sensory stimuli (Olson et al, 2007). Lesions in this structure lead to changes in personality and in social behavior (Thompson et al, 2003). Ablation of the monkey orbitofrontal cortex, TP, and amygdala causes similar socioemotional deficits. To our knowledge, ours is the first study showing 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
