Beyond device parameters: psychological predictors of spinal cord stimulation success and their neurobiological mechanisms—a narrative review

Spinal cord stimulation (SCS) represents an established treatment for refractory chronic pain, yet significant outcome variability persists despite technological advances. This narrative review examines why psychological factors assume central importance in neuromodulation outcomes by establishing pathophysiological contrasts between SCS and pharmacological pain management. Unlike passive pharmaceutical approaches operating through systemic biochemical modulation, SCS requires active patient engagement in device operation, expectancy management, and behavioral adaptation, creating distinct neurobiological requirements for success. Multiple psychological domains predict outcomes. Cognitive factors include pain catastrophizing (the strongest predictor), patient expectations, and cognitive control capacity. Emotional determinants encompass pre-implantation depression, anxiety, and alexithymia. Behavioral patterns such as fear-avoidance, locus of control, and coping strategies significantly influence treatment success. Neuroimaging evidence suggests that these psychological factors modulate response through alterations in prefrontal-limbic circuits, reward processing networks, and cortical reorganization. Maladaptive profiles are associated with reduced prefrontal top-down control, heightened limbic reactivity, impaired mesolimbic reward valuation, and persistent central sensitization. As a narrative synthesis prioritizing conceptual integration over quantitative aggregation, this review: (1) establishes psychological readiness as a neurobiological prerequisite rather than an administrative requirement, (2) delineates mechanisms through which catastrophizing, depression, and fear-avoidance disrupt SCS efficacy via limbic hyperactivity and impaired descending modulation, and (3) presents evidence-based optimization strategies including pre-implantation cognitive-behavioral therapy, acceptance and commitment therapy, behavioral activation, graded exposure, and digital health technologies. Future directions require standardized multidomain assessment protocols, multimodal predictive models integrating psychological phenotypes with objective biomarkers, and expanded digital therapeutics maintaining evidence-based rigor.