https://www.ncbi.nlm.nih.gov/m/pubmed/30267339/
“the present case study applied 20 sessions of EEG neurofeedback to a 45-year-old female and a 30-year-old male, both diagnosed with severe negative symptoms of schizophrenia. In both cases GAF scores were improved significantly and at the end of treatment, both patients did not meet the diagnostic criteria of negative symptomatology any longer. Symptom reduction went along with an obvious improvement of social, interpersonal, and cognitive abilities according to the clinical impression. Detailed data analysis revealed that these improvements went along with corresponding changes of EEG parameters and with distinct patterns and strategies of change in each of the two individuals. The results suggest that EEG neurofeedback should be examined on a larger scale as it offers a promising alternative to existing treatment approaches for negative symptoms in schizophrenia.”