I want any legitimate information on psychological/neurological
reasons for drinking too much water (polydipsia). I will give you
$0.00 for schizophrenia, central diabetes insipidus (also called
neurogenic diabetes insipidus,which I'm not classifying as a neural
ohenomenon), drug-related (including lithium), obsessive, compulsive,
or obsessive compulsive behavior, or any particularly abnormal neural
effects except those directly caused by hyponatremia. Finally, I don't
want anything extremely weird like thinking that aliens are telling
you to drink too much water. Also, the cases or information you find
should not be connected to alcaholism or recreational/prescription
drug use. I am, however, particularly interested in patients who have
developed hypervolemic hyponatremia. I have an extreme and constant
thirst that the doctors think may be neurologically/psychologically
related but they have no basis other than the impulse to blame all
unexplained sicknesses on psychology. I am interested in otherwise
normal people having the sensation that they are very thirsty even
when their bodies don't need that water. Such cases as the following
would be right on the money: actual cases of water dependency, where
one's brain actually has come to depend on too much water. Regulatory
mechanisms in the brain that are offset so as to tell the body that it
needed too much water, or simply a hallucinatory thirst.

You might be a little confused. You've basically ruled out every
single possible explanation of psychogenic polydipsia that is known to
the medical world. Hypervolaemic hyponatraemia is a result/symptom of
polydipsia not a cause in most cases. Drug-related hyponatraemia can
cause polydipsia, but if you're not on any drugs then it has to be a
symptom of the excessive drinking not an aetiology.

Is your hyponatraemia severe enough to be causing headaches,
dizziness, seizures or lethargy?

Apart from schizophrenia, OCD, diabetes, drugs or psychosis there is
no other accepted known cause besides you like water and it's come
sort of compulsion. You could be one of those rare new cases, in which
case I'd recommend you go see a neurologist, endocronologist,
nephrologist or all three.

It could possibly be a ADH/cortisone reflux disease in which case
you're secreting next to no ADH, which is telling your nephrons to
release water causing a thirst, but this is unlikely and You'd know
about such a condition by now!

:)