4. Clinical Trials in Alzheimer’s Disease (texto original)

Abstract
Recent advances in Alzheimer’s disease
imply a need for adequate clinical trials
of new treatments which require careful
design. The disorder is progressive and
shows clinical heterogeneity. While
large-scale trials of elderly subjects are
appropriate in relation to assessment of
drugs or other treatments designed to
prevent progression of the disorder, the
outcome measurements in such
biological treatment trials require
careful planning. Studies of individual
patients are relevant for answering certain
specific questions. Relatively short
cross-over trial designs may be
appropriate to some pharmacological
studies. The choice of neuropsychological
instruments for measuring
change is critically important, particularly
in excluding test/retest artefact
and in avoiding floor and ceiling effects.
Test scales designed for assessment of
specific neuropsychological deficits, or
forming part of standard IQ assessments
are unlikely to prove robust. Tests can be
selected and developed for individual
patients, but generalisation of the results
of such experiments to the disease as a
whole is not inevitable. There is a need to
develop psychological instruments for
measuring change that are robust and
relevant to the clinical problem of
progressive dementia.