We hypothesized that (1) the core pathological alteration in BD is damage of fronto-limbic network that mainly results in emotional dysfunction; (2) that changes in intrinsic brain network, such as SMN, SN, DMN, CEN are associated with alterations of cognitive function; and (3) beyond the dopamine-driven basal ganglia-thalamo-cortical motor circuit modulated by other neurotransmitter systems such as 5-HT (subcortical–cortical modulation), the SMN and related motor function modulated by other non-motor networks such as the DMN are involved in psychomotor function. This evidence concerns the gene HTR5A and Behcet disease.