The severe depressive disorders of late life are associated with
high rates of medical morbidity and
mortality, cognitive impairment, suicide, disability, complex treatment
regimens,
institutionalization and high costs to the community (Murphy, 1983;
Murphy et al. 1988; Bruce & Leaf,
1989; NIH Consensus Development Panel, 1992; Alexopoulos
et al. 1993a, b; Brodaty et al. 1993;
Bruce et al. 1994; Forsell et al. 1994; Hickie et
al. 1995;
Blazer, 1996). Those disorders that are
accompanied by cognitive impairment and/or concurrent medical morbidity
have a particularly
poor outcome (Bruce & Leaf, 1989; Alexopoulos et al.
1993b; Hickie et al. 1995, 1997a). Although
psychosocial models of late-life depression place considerable importance
on age-related
psychological and social risk factors, those who survive into
later life may actually be characterized
by psychological resilience (Henderson, 1994; Blazer, 1997).Current aetiological research in late-life depression, therefore,
places particular emphasis on the
potential role of biological risk factors. The potential importance
of vascular risk factors is receiving
renewed attention and may provide opportunities for specific prevention
and intervention strategies
in high-risk populations. This emphasis on possible vascular
risk factors, and the wider importance
of vascular pathologies in late-life neuropsychiatric disorders,
mirrors the emphasis of much earlier
clinico-pathological studies (Binswanger, 1894; Alzheimer, 1895). The specific
focus on the
importance of small progressive changes within the subcortical
white matter, as distinct from more
discrete cortical infarcts (Olszewski, 1962), is now supported by the emerging
neuroimaging
literature and theoretical constructs in late-life depression
(Krishnan, 1991, 1993; Hickie et al. 1996, 1997b;
Krishnan et al. 1997).
Late-onset depressive disorders: a preventable variant of cerebrovascular
disease?
