Why is it that people on drugs experience negative hallucinations?

Relieve neg. signs: Pts.Wikth substance abuse use drugs to relieve their negative sympotoms. . Using narrow criteria (e.g. Sans), the results of this meta-analysis show that schizophrenia patients with substance fewer negative symptoms than abstinent schizophrenia patients. As such, these results suggest either that substance abuse relieves the negative symptoms of schizophrenia . Lo neg. Symptoms= lo substance.