Hi:

From what I know, none of the current medications for schizophrenia treat the negative symptoms. But, but, but that doesn't mean there isn't treatment for the negative symptoms. There is a branch of talk therapy called Cognitive Behavioral Therapy which has helped me with social interaction. I have heard mindfulness therapy--another branch--can help with lack of motivation although I have never tried it.

Type in google the Academy of Cognitive Therapy and you can find a certified therapist who may help. If you have the concentration to read Schizophrenia by Aaron T. Beck et all is a good read and he is the founder of CBT.