tDCS effects on life engagement in schizophrenia: results from a double-blind sham-controlled trial

Life engagement (LE) is a patient-reported outcome measure (PROM), encompassing emotional, cognitive, social, and physical domains of functioning. While transcranial Direct Current Stimulation (tDCS) significantly improved cognitive and negative symptoms in schizophrenia, its effects on LE remain unexplored. We investigated whether prefrontal tDCS could improve LE in schizophrenia by conducting post-hoc analyses of a randomised, double-blind, sham-controlled trial.

Fifty outpatients living with schizophrenia were randomised to receive either active or sham tDCS (15 weekday sessions, 2 mA, anode: left DLPFC; cathode: right orbitofrontal cortex). LE was assessed using the PANSS-LE, a psychometrically validated subscale derived from the Positive and Negative Syndrome Scale (PANSS). Analyses examined within- and between-group changes, controlling for baseline symptom severity.

Both active and sham-tDCS groups showed significant within-group improvements in LE. However, between-group analysis revealed significantly greater reductions in PANSS-LE scores following active-tDCS, with large effect size (d = 0.97). Moreover, LE improvements were not influenced by baseline levels of negative, cognitive, depressive symptoms, nor by illness severity, suggesting the specificity of LE as a treatment outcome.

This study provides preliminary evidence that prefrontal tDCS may enhance LE in schizophrenia, independently of core symptom domains, supporting the integration of PROMs in neuromodulation research.