103. Altered associative learning-related responses and connectivity of amygdala subnuclei in youth with persecutory ideas

Introduction: Persecutory thinking has been previously linked to changes in the function of the amygdala. To further investigate this potential mechanism of psychosis, we collected fMRI data during a 1) Pavlovian fear conditioning task and 2) a resting-state from healthy young adults with and without persecutory ideas. Methods: During fear conditioning, one face stimulus (CS+) was followed by an electrical shock while another (CS-) was not. Persecutory beliefs were measured using the Peters et al. Delusions Inventory. FMRI data were analyzed using FreeSurfer v6, with an automated anatomical segmentation procedure that delineated the boundaries of amygdala subnuclei. Results: The participants without (P- group, N = 46) but not those with (P+ group; N = 26) persecutory beliefs showed significant conditioning-related fMRI responses in the amygdala, most strongly in the accessory-basal and corticoamygdaloid nuclei. Moreover, these two amygdala nuclei showed significantly weaker connectivity to the striatum in the P+, compared to the P-, group. Conclusion: These findings provide further evidence for abnormal amygdala function in psychotic states, suggesting that disruptions of associative learning processes that rely upon medial amygdala nuclei, as well as changes in their projections to the striatum, may play a role in the neural mechanisms of psychosis.