Combining HD-tDCS and iTBS in Treating Negative Symptoms of Schizophrenia

Dysfunction of the left dorsolateral prefrontal cortex (DLPFC) is central to the persistence of negative symptoms in schizophrenia, an area of unmet therapeutic need. High-definition transcranial direct current stimulation (HD-tDCS) and intermittent theta burst stimulation (iTBS), an optimized form of repetitive transcranial magnetic stimulation (rTMS), have each demonstrated efficacy in alleviating negative symptoms when applied to the left DLPFC. However, meta-analyses indicate only moderate effect sizes for these interventions individually. Evidence suggests that combining iTBS with tDCS may enhance cortical plasticity beyond either technique alone, warranting trials to assess additive efficacy. This double-blind, randomized, sham-controlled study will test the hypothesis that combined HD-tDCS and iTBS produce superior therapeutic benefit for negative symptoms in schizophrenia.