Background. Cross-sectional studies of non-cognitive symptoms
in dementia show that patients
with psychotic symptoms tend to have more disturbed behaviour. However,
it is not known whether
individuals who experience psychiatric symptoms early in dementia are more
prone to develop
behavioural problems later in the illness.
Method. The behaviour of 86 community-dwelling subjects with
dementia was intensively studied
for 4 years or until death, using an informant interview which was
administered every 4 months on
a median of eight occasions. The extent to which psychiatric symptoms,
age, sex and cognitive
function predicted clinically significant physical aggression
or motor hyperactivity was assessed.
Results. Physical aggression was predicted by sad
appearance and motor hyperactivity was
predicted by persecutory ideas. These associations were robust,
remaining significant over 2, 3 and
4 years of follow-up and were independent of cognitive function,
age, sex and duration of illness.
Conclusions. There may be two distinct longitudinal
syndromes of non-cognitive symptoms in
dementia. This suggests that important aberrant behaviours in late dementia
may share
pathophysiological mechanisms with psychiatric symptoms in early dementia.