Reward networks changes in the brain of pathological gamblers: a resting state functional magnetic resonance imaging study

Aims and objectives To investigate functional connectivity changes in pathological gamblers (PGs) in comparison to healthy controls (HCs) by means of resting state functional Magnetic Resonance Imaging (RS-fMRI). Methods and materials Thirteen HCs and fourteen PGs were recruited (all right handed males; drugs free; mean age 35.96±9.56). All subjects underwent brain scan using a 1,5T MRI scanner. Activations data of functionally linked brain regions were obtained using a multi-session temporal concatenated Independent Component Analysis (concat-ICA). The resulted components were than matched and compared between groups. Correction for multiple comparisons across space was applied assuming an overall significance of p < 0.05 using permutation testing and threshold-free cluster enhancement. Results In PGs subjects, compared to HCs, we found an increased functional connectivity in several networks including: anterior cingulate cortex, accumbens nucleus, head of the caudate nucleus, middle left temporal gyrus, right insula, right cerebellar hemisphere cortex and cerebellar vermis. Conclusion Our study has showed an hyperconnectivity together with an overactivation of specific regions in PGs. The presence of increased functional connectivity in brain regions involved in the processing of rewards and external stimuli, in the attribution of spatiotemporal characteristics to events significance, and the resulting decision-making process, confirms the neurofunctional basis underlying clinical features of gambling disorder. PGs may therefore exhibit a state reduced triggering threshold to gaming due to a persistent activation of specific functional networks recruited during gambling tasks.