Efficacy and Tolerability of Lesion Network Guided Transcranial Electrical Stimulation in Outpatients with Psychosis Spectrum Illness: A Nonrandomized Controlled Trial

ImportanceTranscranial electrical stimulation (tES) may improve psychosis symptoms, but few investigations have targeted brain regions causally linked to psychosis symptoms. We implemented a novel montage targeting the extrastriate visual cortex (eVC) previously identified by lesion network mapping in the manifestation of visual hallucinations. ObjectiveTo determine if lesion network guided HD-tES to the eVC is safe and efficacious in reducing symptoms related to psychosis. Design, Setting, and ParticipantsSingle-center, nonrandomized, single-blind trial using a crossover design conducted in two 4-week phases beginning November 2020, and ending January 2022. Participants were adults 18-55 years of age with a diagnosis of schizophrenia, schizoaffective or psychotic bipolar disorder as confirmed by the Structured Clinical Interview for DSM-V, without an antipsychotic medication change for at least 4 weeks. A total of 8 participants consented and 6 participants enrolled. Significance threshold set to <0.1 due to small sample size. Interventions6 Participants first received HD-tDCS (direct current), followed by 4 weeks of wash out, then 4 received 2Hz HD-tACS (alternating current). Participants received 5 consecutive days of daily (2 x 20min) stimulation applied bilaterally to the eVC. Main Outcomes and MeasuresPrimary outcomes included the Positive and Negative Syndrome Scale (PANSS) total, positive, negative, and general scores, biological motion task, and Event Related Potential (ERP) measures obtained from a steady state visual evoked potential (SSVEP) task across each 4-week phase. Secondary outcomes included the Montgomery-Asperg Depression Rating Scale (MADRS), Global Assessment of Functioning (GAF), velocity discrimination task, visual working memory task, and emotional ERP across each 4-week phase. ResultsHD-tDCS improved general psychopathology in the short-term (d=0.47; pfdr=0.03), with long-term improvements in general psychopathology (d=0.62; pfdr=0.05) and GAF (d=-0.56; pfdr=0.04) with HD-tACS. HD-tDCS reduced SSVEP P1 (d=0.25; pfdr=0.005), which correlated with general psychopathology ({beta}=0.274, t=3.59, p=0.04). No significant differences in safety or tolerability measures were identified. Conclusions and RelevanceLesion network guided HD-tES to the eVC is a safe, efficacious, and promising approach for reducing general psychopathology via changes in neuroplasticity. These results highlight the need for larger clinical trials implementing novel targeting methodologies for the treatments of psychosis. Trial RegistrationClinicalTrials.gov Identifier: NCT04870710 Key PointsO_ST_ABSQuestionC_ST_ABSIs lesion network guided neurostimulation an efficacious, safe, and targeted approach for treating psychosis? FindingsIn this single-center, nonrandomized, crossover, single-blind trial of 6 outpatients with psychosis, improvement in general psychopathology was seen in the short-term with HD-tDCS (high-definition transcranial direct current stimulation) and long-term with HD-tACS (alternating current) targeting the extrastriate visual cortex (eVC). HD-tDCS reduced early visual evoked responses which linked to general psychopathology improvements. Overall, both stimulations were well tolerated. MeaningStudy findings suggest that lesion network guided HD-tES to the eVC is a safe, efficacious, and promising approach for reducing general psychopathology via neuroplastic changes.