Deficit (negative symptoms) schizophrenia seems to be associated with white matter alterations/disruptions/loss. I found an article that says that meditation can increase white matter connectivity…It might be worth giving meditation a shot. The length of the meditation sessions should be of about 30 minutes, once per day
Article about White matter and deficit schizophrenia–>
w w w .ncbi.nlm.nih.gov/pmc/articles/PMC4530339/
Article about Meditation and White Matter–>
w w w .ncbi.nlm.nih.gov/pmc/articles/PMC4209813/
Abstract
Training can induce changes in specific brain networks and changes in brain state. In both cases it has been found that the efficiency of white matter as measured by diffusion tensor imaging is increased, often after only a few hours of training. In this paper we consider a plausible molecular mechanism for how state change produced by meditation might lead to white matter change. According to this hypothesis frontal theta induced by meditation produces a molecular cascade that increases myelin and improves connectivity
Anyway, some studies claim that cognitive behavioral therapy is also effective to some extent against negative symptoms.