Psychotic and depressive symptoms in Parkinson's disease. A study of the growth hormone response to apomorphine.
BACKGROUND
The growth hormone (GH) response to apomorphine, thought to reflect central dopaminergic receptor sensitivity, has been reported as enhanced in acute schizophrenia. We investigated this response in relation to the psychotic episodes associated with Parkinson's disease (PD).


METHODS
The GH response to apomorphine was measured in three groups of patients with Parkinson's disease: those currently psychotic (n = 9), those with a past history of psychosis (n = 7) and those who had never been psychotic (n = 8).


RESULTS
Apomorphine-induced GH response was not related to psychosis but was unexpectedly associated with measures of depression.


CONCLUSIONS
Visual hallucinations were a prominent feature in the psychotic patients and the atypical nature of these psychoses might explain why we found no evidence of dopaminergic sensitivity. Serotonergic dysfunction would be in keeping with this. Dopaminergic mechanisms may contribute to the minor depressive symptomatology seen in PD.
Mellers
J D
JD
Section of Neuropsychiatry, Institute of Psychiatry, London.
Quinn
N P
NP
Ron
M A
MA
D000368:Aged; D001058:Apomorphine; D003866:Depressive Disorder / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D005260:Female; D013006:Growth Hormone / Q000097:blood*; D006212:Hallucinations / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology; D006801:Humans; D008297:Male; D008875:Middle Aged; D019965:Neurocognitive Disorders / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D010300:Parkinson Disease / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D011954:Receptors, Dopamine / Q000187:drug effects / Q000502:physiology*; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology; D012016:Reference Values
D011954:Receptors, Dopamine; D011985:Receptors, Serotonin; D013006:Growth Hormone; D001058:Apomorphine