Dopamine correlates of neurological and psychological status in untreated Parkinsonism

Thirty-seven untreated Parkinsonism patients showed significant positive correlations among decreased excretion of free dopamine, MMPI scores indicative of schizophrenic-like looseness of thinking, and the severity of all Parkinsonism signs except tremor. The data could indicate that abnormalities of dopamine metabolism may underlie both the motor and mental abnormalities of Parkinsonism.