This is a prospective observational study to investigate the impact of spinal cord stimulation (SCS) procedure in chronic pain perception and management. Patients' psychological status at different time points and its correlation with pain outcomes and satisfaction with the SCS intervention will be also evaluated. The primary aim is to study the associations between psychological variables and intervention outcomes (pain reduction, satisfaction, removal of SCS). Our hypothesis is that people with higher scores in anxiety and depression symptoms would report lower satisfaction with SCS procedure and higher levels of perceived pain after the implantation of the device