Depue & Collins's (D&C's) work relies on
extrapolation from data obtained through studies in experimental
animals, and needs support from studies of the role of dopamine (DA)
neurotransmission in human behaviour. Here we review evidence from two
sources: (1) studies of patients with Parkinson's disease and (2)
positron emission tomography (PET) studies of DA neurotransmission,
which we believe lend support to Depue & Collins's theory,
and which can potentially form the basis for a true neurochemistry of
personality.