Secondary Schizophrenia (81 page)

paranoid symptoms in senile dementia patients as
dementias are less common than in

being poor, unstable, and lacking in judgment
[8].
In
Alzheimer’s Disease.

1930, W. Runge contributed the observation that paranoid symptoms in patients with senile dementia were
facilitated by hearing loss
[9].

The association between impaired cognitive abil-

ity and delusional thinking in dementia was further
Although descriptions of psychotic symptoms in senile
emphasized by Gertrud Jacob in 1928
[10].
She argued
dementia existed in earlier reports, Emil Kraepelin
that the apperception of reality becomes increas-documented delusions, illusionary misidentifications,
ingly vague and fragmented, allowing emotionally
and hallucinations as part of the clinical picture in
charged imaginations to occupy the foreground of
some detail
[1]
. He characterized psychotic symp-consciousness. Hans Lauter also maintained in 1968

toms of dementia patients as simple, unelaborated,
that, in contrast to schizophrenia, delusions in demen-fluctuating, inconsistent, and often contradictory. The
tia retain a close connection with reality, lack system-most frequent delusional contents were described as
atization, and are related to the loss of intellectual
204

being hypochondriac concerns, unwarranted mistrust
ability
[11].

Chapter 15 – Neurodegenerative disorders

Table 15.1
Comparison of psychosis in AD and schizophrenia
Table 15.2
Proposed diagnostic criteria for “psychosis of
in older adults

Alzheimer’s Disease”
[13]

Schizophrenia

Characteristic symptoms

Presentation

Psychosis in AD

in old age

Presence of visual or auditory hallucinations and/or delusions.

Complex delusions

Rare

Common

Primary diagnosis

Type of

Visual > auditory

Auditory > visual

Clinical criteria for AD are met.

hallucination

Chronology of onset of symptoms of psychosis

Misidentifications

Common

Rare

Psychotic symptoms have not been present continuously prior
Schneiderian

Rare

Common

to the onset of dementia.

first-rank symptoms

Duration

Suicidal ideation

Rare

Common

Psychotic symptoms have been present (even if intermittently)
History of psychotic

Rare

Common

for at least 1 month.

symptoms

Severity

Adapted from Jeste and Finkel, 2000
[13].

Psychotic symptoms are severe enough to affect patients’ or
others’ level of functioning.

Exclusion of other psychotic disorders

Definition and clinical features

Criteria for schizophrenia or other functional psychiatric
disorders with psychotic symptoms have never been met.

Psychotic symptoms in Alzheimer’s Disease

Psychotic symptoms are also not better explained for by other
medical conditions.

Psychotic symptoms in AD differ from those typi-

Relationship to delirium

cally seen in schizophrenia. The most common psychotic symptoms observed in patients with AD are
The psychotic symptoms do not occur exclusively in the
context of a delirium.

delusions, delusional misidentifications, and halluci-Adapted from Jeste and Finkel, 2000
[13].

nations. Delusions tend to be simple and of the paranoid type. Burns and colleagues identified delusions of
theft as the most common form, followed by delusions
Evidence of associations of psychotic symptoms
of suspicion
[12].
Around 20% of AD patients in their
with specific stages of the illness is inconsistent
[14],

study had experienced persecutory ideas. Misidentifi-although more complex delusions have been described
cations are common in AD. In reduplicative phenom-in patients with better preserved intellectual functions
ena, which may be temporal, personal, or environ-

[15].
Visual hallucinations have been associated with
mental, patients believe that a place, person, or time
severe AD
[16].

exists more than once or has been replaced by some-There has been a recent attempt to establish spe-thing else. These include syndromes such as the Cap-cific diagnostic criteria for the psychosis of AD, to
gras syndrome, in which the patient is convinced that a
help improve diagnostic consistency for communica-familiar person has been replaced by an impostor, and
tion in the areas of epidemiology, diagnosis, man-the Frégoli syndrome, in which an unknown person is
agement, and research.
Table 15.2
list the criteria
believed to be someone familiar. Misidentifications of
suggested by Jeste and Finkel
[13]
. The authors point
television and mirror images are also common. Hal-out that the psychosis can be associated with agitation,
lucinations are less common than delusions.

depressive symptoms, or negative symptoms. They also
Unlike schizophrenia, hallucinations are more

stress that the clinical usefulness of these criteria relies
often visual than auditory, and when auditory they
on the experience and judgment of the clinician apply-usually lack the complexity described in the Schneide-ing them, for example, confabulations may be con-rian first-rank symptoms. In contrast to schizophrenia,
fused with delusions by some. The criteria were pro-suicidal ideation or suicide attempts due to psychotic
posed as guidelines to help clinicians to distinguish
symptoms are uncommon in AD, as is a history of psy-psychosis in AD from other primary psychotic disor-chotic symptoms prior to the onset of AD
[13].

ders and delirium.

Table 15.1
describes typical differences between
Lyketsos and colleagues proposed a different

psychotic features in AD and older adults with
approach. Based on data from the Cache County

205

schizophrenia.

Study using a latent class analysis, several subgroups
Organic Syndromes of Schizophrenia – Section 3

Table 15.3
Diagnostic criteria for “Alzheimer-associated
between different mutations, but also within a single
psychotic disorder”

family
[30].
Bird and colleagues described a family
A. Alzheimer’s Disease according to NINDS/ADRDA criteria
with an autosomal-dominant pattern of inheritance of
B. Delusions or hallucinations that have an impact on the
a dementia syndrome in which affected family mem-patient’s behavior and his care.

bers developed schizophrenia-like symptoms in the
C. One or more associated symptoms must be present:
fifth or sixth decade
[31],
often leading to an initial
depression, irritability, anxiety, euphoria, aggression, and/or
diagnosis of schizophrenia. The psychotic symptoms
psychomotor agitation.

were described as “suspiciousness, paranoid ideas,
D. Duration must be 2 weeks or longer.

auditory hallucinations, loose associations, and intruE. Should occur in a temporal relationship with the cognitive
sive thoughts” associated with social withdrawal, com-symptoms.

pulsions, and aggressive behavior. The clinical presen-F. Can not be explained by other causes.

tation of affected family members of the same family
Adapted from Lyketsos
et al.
(2001)
[17].

has been described elsewhere in more detail
[32, 33].

Autopsy revealed the presence of neurofibrillary tan-gles (NFT) in several regions such as the neocortex,
of patients with AD were identified according to their
amygdala, and parahippocampal gyrus.

neuropsychiatric symptoms measured with the Neu-This family showed a strong linkage to the marker
ropsychiatry Inventory (NPI)
[17].
Table 15.3
lists
D17S934 and the V337M mutation was identified as
the criteria for the psychotic subgroup. The authors
the causative mutation.

favor this empirical approach because their proposed
method to identify clusters of symptoms allows for co-occurrence of neuropsychiatric symptoms.

Prevalence and incidence

It also has been suggested that a further subclassi-Prevalence and incidence rates for psychotic symp-fication of the psychotic syndrome might be clinically
toms in AD differ depending on whether the data are
relevant. Investigators from Pittsburgh identified two
based on population based or clinical samples, partly
psychotic subtypes: a “misidentification subtype” and
explaining the wide ranges in published reports. Delu-a “persecutory delusions subtype,” which showed dif-sions have been reported to occur in 10%–73% and
ferent profiles of cognitive impairment
[18, 19].

hallucinations in 3%–49% of patients with AD
[34].

In a recent review of 55 studies by Ropacki and Jeste,
Psychotic symptoms in frontotemporal

the overall prevalence for psychotic symptoms in AD

was estimated as 41%, with 36% of patients experienc-dementias
ing delusions and 18% hallucinations
[35].
Delusional
Descriptions of specific psychotic symptomatology in
misidentifications have been reported to be present in
patients with frontotemporal dementias (FTD) are
up to 30% of patients with AD
[12,
36, 37].

sparse in the recent literature, and it has been sug-Psychotic symptoms have been shown to co-occur
gested that hallucinations are an uncommon clinical
with other neuropsychiatric symptoms, such as aggres-presentation for tauopathies
[20].
However, Gustafson
sion, agitation, apathy, and depression
[38].
Bassiony
and colleagues reported psychotic symptoms in up to
and colleagues, for example, found that the presence
20% of all patients with FTD
[21],
and delusions have
of depression significantly increased the risk for delu-also been reported in FTD, usually in association with
sions in their 303 patients with AD living in the
a more prominent atrophy of the right anterior tempo-community (OR
=
6.8, 95% CI
=
2.1–21.6)
[39].

ral lobe
[22].

Incidence rates for psychotic symptoms in AD are
Psychotic symptoms have been reported in some of
lower in population-based studies as compared to clin-the more rare, familial FTDs. One such group is “fron-ical studies.

totemporal dementia with parkinsonism linked to
Lyketsos

and

colleagues

reported

for

the

chromosome 17” (FTDP-17)
[23, 24],
which accounts
community-based Cache County Study an annual

for 6%–18% of all FTDs
[25, 26, 27],
and for which
incidence rate of 18% for delusions and 11% for hallu-more than 30 tau mutations in more than 80 fami-cinations
[17],
whereas Paulsen and colleagues found,
lies have been reported
[28].
Chromosome 17 muta-in a longitudinal study of clinic patients with AD

206

tions can lead to a broad variety of phenotypes
[29]

who did not show psychotic symptoms at study entry,
Chapter 15 – Neurodegenerative disorders

an increasing overall incidence rate for psychotic
Table 15.4
Neurobiological factors discussed for psychosis
symptoms (20% at year 1, 36% at year 2, and 50% at
in AD

year 3)
[40].

Delusions and misidentifications

• Basal ganglia calcification [12].

Risk factors and outcomes

• Lower neuronal counts in the hippocampus (CA1) [44].

Many risk factors for psychotic symptoms have been
• Elevated muscarinic M2 receptor binding in the cortex [45].

discussed in the literature, but the results frequently
• Temporal lobe asymmetry [46].

differ depending on characterization of risk factors,
• Metabolic and perfusion abnormalities in frontal, temporal,
nature of patient cohort, methods of analysis, and the
and parietal cortex [47, 48, 49].

interpretation of the results
[41].
The finding that psy-

• Serotonin receptor 5-HT2A polymorphism 102T [50].

chotic symptoms are less common in advanced AD