Neurophysiological Markers in the Depressive Episode Characterized by Anhedonic Drug Resistance: Evaluation of Motor Skills and P300 Wave

Depression is currently the leading cause of disability and suicide death worldwide. Several studies, however, have shown that a significant proportion of patients do not respond to standard antidepressants, especially since their symptomatology is dominated by anhedonia or psychomotor retardation reflecting central dopaminergic dysfunction. In order to improve the efficiency and speed of the antidepressant response, it seems essential to highlight this dopaminergic dysfunction, by defining a P300 wave profile specific to the subtype of depressed patients with anhedonic phenotype to whom personalized treatment targeting dopaminergic transmission could in the future be proposed earlier. The investigators therefore wish to highlight an increase in the latency time of P300 and a modification of motor skills (of the walking cycle and of the movement of the hands), without modification of the dopaminergic transmission measured by PETScan, specific to the sub-type of depressive patients, resistant to at least 2 antidepressants of different classes with an anhedonia score\> 5/14 on the SHAPS scale. The increased latency of P300 could then be used in the future as a predictive biomarker of resistance to conventional antidepressant treatments specific to this population of anhedonic depressed patients