Can I ask what age-bracket you fall into?
Because its drug induced Schizophrenia, Im wondering did you experience any Florid Symptoms, at first at all, or was it just negative symptoms?
You said it was an 'insiduous onset' so did it
seem like depression and turn into a more catatonic state or??
What I know is the negative
usually follows the positive symtoms in Schizophrenics but this depends on certain factors.
I do know people who have got better with treatment.(anti-psychotics, anti -depressants, psychotherapy and staying off non-perscribed substances; have all seemed to help this happen) ...although the anti-psychotics dont pertain to your situation with the negative symptoms ATM.
Is there any genetic predisposition to Schizophrenia or do you believe it occured primarily because of the MDA use?
Just concerned that amphetimine use, although treating the catatonic symptoms as they are now, might not do much good for you long term, and may even hinder your recovery long term? Am not a Docter so I dont know. Have you been given a brain scan? Are you receiving any other kind of therapy to help you longterm?
Always cautious about quick fixes when it comes to drug induced mental illness'!

Just throwing that out there.