Major depressive disorder (MDD) and frontotemporal dementia (FTD) are
both disorders in elderly populations that involve the prefrontal
cortex and appear to have similar neurocognitive deficits. This review
examined whether there are testable deficits in cognition that are
consistent across individuals within the same neuropathological
condition that could be used to facilitate early diagnoses. Medline and
PsychInfo databases were searched for cognitive studies of depressed
and FTD patients that used a matched control group and reported
findings with means and standard deviations (N = 312). Effect
sizes for FTD patients with mild and moderately advanced disease were
compared to effect sizes within subgroups of depressed patients, such
as inpatients, outpatients and community volunteers. Moderately
advanced FTD patients were more impaired than depressed patients over
all domains, particularly in language ability, although depressed
inpatients appeared similar to FTD patients in some domains. Effect
sizes for FTD patients who were in the mild, or early, stage of the
disease (MMSE = 28) were similar to those of depressed
outpatients but slightly worse than those of community volunteers in
all domains except semantic memory and executive ability. In the latter
two domains, even mild FTD patients had notably large deficits. All FTD
patients showed more severe deficits in some domains relative to other
domains. In contrast, depressed patients tended to vary by clinical
presentation or disease severity, but the magnitude of impairment for
each subgroup remained relatively consistent across domains and they
did not have the severe focal deficits in one or two domains
demonstrated by FTD patients. (JINS, 2004, 10,
753–771.)