Improving the early diagnosis of Alzheimer*s disease and other dementias

The differential diagnosis of mental complaints that may signify an early stage
of dementia is notoriously difficult. One reason for this difficulty is that
the transition between normal cognitive aging and cognitive impairment due to
degenerative cerebral disease is a gradual one. A second reason for the
diagnostic difficulty is the frequent co-occurrence of cognitive impairment and
emotional-behavioural or psychiatric symptoms. Estimates of this co-occurrence
in pre-dementia patients vary from 25% in population-based studies to more than
60% in clinical samples. This causes frequent misclassification of pre-dementia
and functional psychiatric states in elderly patients. There is a relative lack
of research that takes this co-occurrence into account. Dementia researchers
often evade the problem by excluding patients with psychiatric disorders, while
psychiatry researchers evade it by limiting the age range in their studies or
by excluding patients with cognitive impairment. This state of affairs does not
do sufficient justice to clinical reality. The present research project
expressly addresses the co-occurrence of cognitive and emotional-behavioural
symptoms.

To improve the behavioural (neuropsychological) methods for the early diagnosis
of Alzheimer*s disease (AD) and other dementias.

Standard neuropsychological tests with proven validity for the early detection
of dementia will be adapted to increase their precision of measurement. These
improved tests, plus structured psychiatric assessment, and Symptom Validity
Testing (SVT) will be applied to distinguish (1) patients with mental
complaints secondary to degenerative brain disease from (2) patients with
mental complaints that are probably due to non-organic influences, i.e.
emotional-behavioural problems and functional psychiatric disorders.
Structural MRI scans will be made at baseline, and blood samples will be
collected and stored for later neurogenetic and neurochemical analysis.
Patients will be followed-up biannually.
Controls will be given the improved neuropsychological test only.

Two visits to the AMC at baseline (max 3 hours each): neuropsychological
testing, psychiatric interview, MRI scan, blood sampling (once; three tubes of
7 ml each).
Brief visits to the AMC biannually (max 1 hour each; brief interview and brief
neuropsychological testsing; max 3 visits) until a change in clinical status
has occurred.
There are no risks involved.
Benefit of the individual patient may be new diagnostic findings that are
directly relevant to the treatment.