For the last few years My grown up Son who has Autism has been suffering from hallucinations and audio disturbances which are really distressing for him. We were told it is caused by severe anxiety but this isn't always the case. He has tried various medications but nothing seems to be able to keep him stable for long and he has even been admitted to psychiatric hospitals in the past.. I have just been told by the Doctor that it isn't really a form of Psychosis but more to do with his Autism. I looked up Autism and hallucinations on the internet and read that reduced levels of the neurotransmitter GABA can cause hallucinations etc. Does anyone else have any experience with this and if so what are the testing methods and treatment?