the WHO study and the fact that many people with schizophrenia recover from schizophrenia (or schizophrenic symptoms) without neuroleptics doesn't have any bearing on whether they also have ventricular enlargement.

it could be the case that they do have degenerative ventricular enlargement.

the only way to rule that out would be to neuroimage them and find out...

we do know that people without schizophrenia have ventricular enlargement and that people with schiozphrenia don't have ventricular enlargement.

randomised double blind control trials are considered to be the best scientific methodology because they are much more effective in ruling out alternative hypotheses than other kinds of trials. in particular, if we had a group on neuroleptics and a control group (matched for severity) not on neuroleptics and we neuroimaged them progressively over time then the study would presumably show whether the degeneration that was found was due to the neuroleptics or neural degeneration that occurs in the absence of neuroleptics. we need the control group to fix the base rate...