@entity308 is a debilitating @entity146 characterized among other aspects by the inability to properly experience or respond to reward. However, it remains unclear whether @entity1 with @entity308 present @entity73 due to abnormal modulatory mechanisms. We investigated the activation of the nucleus accumbens (NAcc), a crucial region involved in reward processing, with functional magnetic resonance imaging using the desire-reason-dilemma paradigm. This task allows tracking the activity of the NAcc during the acceptance or the rejection of previously conditioned reward stimuli. @entity1 were assigned into subgroups of lower (LA) or higher ( @entity15773 ) NAcc activation according to beta weights. LA @entity1 presented significant hypoactivation in the ventral tegmental area in addition to bilateral ventral striatum, confirming impairments in the bottom-up input to the NAcc. Conversely, @entity15773 @entity1 presented significant hyperactivation in prefrontal areas such as the rostral anterior cingulate cortex and the anterior ventral prefrontal cortex in addition to bilateral ventral striatum, suggesting disturbances in the top-down regulation of the NAcc. Demographic and clinical differences explaining the abnormal co-activations of midbrain and prefrontal regions were not identified. Therefore, we provide evidence for dysfunctional bottom-up processing in one potential neurobiological subtype of @entity308 (LA) and dysfunctional top-down modulation in another subtype ( @entity15773 ). We suggest that the midbrain and prefrontal regions are more specific pathophysiological substrates for each @entity308 subtype. Above all, our results encourage the segregation of @entity1 by similar dysfunctional mechanisms of the dopaminergic system, which would finally contribute to disentangle more specific pathogeneses and guide the development of more personalized targets for future therapies.

Dissociating pathomechanisms of XXXX with fMRI: bottom-up or top-down dysfunctions of the reward system.

@entity1 :: ('9606', 'Species') :: ['Patients', 'patients'] @entity308 :: ('MESH:D003866', 'Disease') :: ['Depression', 'depression'] @entity146 :: ('MESH:D001523', 'Disease') :: ['psychiatric disorder'] @entity73 :: ('MESH:D003072', 'Disease') :: ['impaired reward system'] @entity15773 :: ('MESH:C537629', 'Disease') :: ['HA']
@entity308 :: (MESH:D003866,Disease) :: ['depression']
