© ViralnovaSeries of drawings by a schizophrenic illustrating how his perceptions changed as the episode became more severe. Image borrowed from this Viralnova page (http://www.viralnova.com/schizophrenic-art/), which includes other examples of schizophrenic art.
An NPR report tells us,
People with schizophrenia — more than 21 million worldwide — tend to have less gray matter and fewer connections in their brain than healthy peers. But scientists aren't sure why. The research, for the first time, suggests that variations in a gene called complement component 4, or C4, for short, could be important. The gene had previously been known to help the immune system target infections.What struck me about this story was the first sentence I quoted — that schizophrenics usually have "less gray matter and fewer connections in their brain" than other people. The new discovery suggests that a genetic malfunction causes the brain to clear away too many synaptic connections (a process called synaptic pruning).
A mutant form of the gene makes proteins that tag an excess number of brain synapses for destruction. This explanation meshes neatly with the tendency of schizophrenia to arise during adolescence, a period during which even healthy brains are busy pruning lots of connections.
Comment: Further reading: Scientists discover possible biological cause of schizophrenia that could lead to cure