I think that you need to be clear which categories of psychosis you are
discussing. However, both cylothymic and the schizophrenia-parkinson axes are
indeed highly bipolar, although the latter tends to be collapsed into one or
the other states, depending on dopamine levels. It is striking how overdosing
with LDOPA can push a completely locked up Parkinson sufferer into something
close to acute psychosis. The effects of carbon dioxide inhalation (or low
oxygen, CO2 purged air) in creating temporary lucidity is well known, as are
the kick-starts of cold and electroshock, insulin coma and the like. In the
pre-triazine days, social and other shocks were noted for their precipitative
This said, it is clear that there is a profound biochemical base for most
psychosis which is not linked to physical abnormalities, intoxication, brain
degeneration and the like, with a strong element of heritability of this.
That the system once perturbed behaves as though there were attractors is
certainly open to debate and this may be a useful way to think about
management of patients. One would therefore have to see the fit state as a
dominant attractor in a surface which is altered by physiological
circumstance. At issue: two attractors or somply a pitted surface, covered
with many weak attrcators. The ethymology of schizophrenia - the shattering,
the lack of focus - would suggest that this is a reasonabel picture.
Cyclothymic depression is different, however, and seesm bipolar. Parkinsonism
(whilst not a psychosis, but essentially anti-schizophrenia) manifests very
strong attractors with sharp physical expression:occulogyria and so forth.