Explanations of abnormal behavior that emphasize the importance of
physiological determinants of disorder are relatively unpopular among
psychologists, especially among those who work as clinicians in an ap
plied setting. The reasons for this are theoretical and historical, as
well as practical. Physiology and its associated biological disciplines
of bio chemistry, pharmacology, and genetics are traditionally more
associated with medicine; their use to underpin explanations and
treatments of behavioral abnormality has consequently demanded knowledge
to which most psychologists are not exposed and skills that are
unavailable to them. The dichotomy thus created between medical and
psychologi cal approaches has caused many psychologists to disregard
physiologi cal factors. Even when the latter are recognized as
important, many psychologists have been unwilling to admit to the fact,
in the belief that by doing so they will commit themselves to an overly
medical model of psychological disorder, undermining what they see as
preferred views of abnormality. As I have become increasingly aware in
following the progress of this book, in the United States the
theoretical issues in this debate have been further sharpened by
professional rivalries (present but less explicit on the European scene
from which I write) between medical and nonmedical health care workers,
regarding facilities for and approaches to the treatment of the mentally
disturbed. Faced with these divisions of interest, psychologists have
available two courses of action.