Several of the tests previously used to predict which elderly individuals risk developing dementia do not seem to work any longer. The thesis shows that memory loss is the only factor that can still be used to indicate who is at risk, although not among the very old.
The study compared nondemented 70-year-olds examined in the early 1970s with nondemented 70-year-olds examined in the year 2000. The results show that those who were examined in 2000 scored much higher on psychological tests than those examined 30 years earlier. This finding clearly indicates that such tests can no longer be used to predict future dementia.
– In the early 1970s, several different tests could be used to predict people’s risks of developing dementia, but today it seems like psychiatric evaluation of the memory is the only useful test. In addition, it is more difficult to predict dementia the higher the person’s level of education, says physician PhD Simona Sacuiu, the author of the thesis.
The follow-up of the 70-year-olds five years later showed that 5% had developed dementia. Those with memory problems showed an increased risk of developing dementia, although not everybody with poor memory developed dementia. Consequently, the link between forgetfulness and future dementia is more complex than commonly thought. Memory loss among elderly individuals may, but doesn’t have to be, an early sign.
– In order to effectively detect dementia at an early stage, we need a useful tool that includes several types of tests, but the tests need continuous adjustments since the elderly of today perform much better at standardised psychological tests than previous generations, says PhD Sacuiu.
Examinations of a group of nondemented 85-year-olds show that the link between memory problems and dementia is not as clear in this age group. The 85-year-olds’ ability to find words, to copy a geometric figure and to take quick decisions were some qualities that were evaluated in a psychiatric assessment. More than 300 individuals participated in the study, of which 17% had developed dementia three years later.
– We can’t say that memory loss is the only meaningful sign of future dementia among 85-year-olds, since other symptoms, such as difficulties finding words or drawing a geometric figure, were needed for their risk of developing dementia to increase, says Sacuiu.
The H70 study
H70, short for Health 70, is a unique population study at the Sahlgrenska Academy. The study was started in 1971 with an assessment of 70-year-olds. The individuals were followed up regularly for 30 years. A new H70 study was started in the year 2000. Its participants will be followed up again during 2009 at age 79. The study includes data on over 2000 residents of Gothenburg, Sweden. The participants have been examined both physically and mentally, and have made it possible for several research teams to pinpoint various trends in physical and mental health in the ageing population.
Doctoral thesis for the degree of Doctor of Philosophy (Medicine) at the Sahlgrenska Academy at University of Gothenburg, Institute of Neuroscience and Physiology, Neuropsychiatric Epidemiology Unit.
Title of the thesis: Prodromal Cognitive Signs of Dementia