ABSTRACTS - World Psychiatric Association

carry on studying these psychoses with modern strategies and technologies.
Cycloid psychoses are hypothesised as being a spectrum of
neurodevelopmental disorders placed between the (bipolar) affective
and the schizophrenic spectrum of psychoses.
RS9.
RECENT ADVANCES IN PSYCHIATRIC GENETICS
RS9.1.
GENETIC PREDICTORS OF ILLNESS
AND TREATMENT RESPONSE
A. Serretti
Institute of Psychiatry, University of Bologna, Italy
The recent rapid developments in psychiatric genetic research produced
more confusion than clarity in many researchers even in the
same field. The supposed effect of gene variants in psychiatric disorders
changed during the last couple of decades. Initial findings suggested
that single gene variants could be a sufficient cause of bipolar
disorder or schizophrenia. The following disillusionment leaded to
the hypothesis of genes as at least a cause of a subtype of each disease.
Also this hypothesis was not confirmed, and during the last few years
the huge technical advances flooded journals with a large number of
scattered associations in many different directions. For schizophrenia,
a few susceptibility genes (including dysbindin, neuroregulin-1,
DAOA, DISC-1) have been consistently replicated across different
samples. A similar situation exists for bipolar disorder (BDNF,
DAOA, FAT, HTTLPR among the others). Depression, anxiety, and
the rest of adult and child disorders, as well as personality disorders,
are much less informative. Focusing on pharmacogenetics, again a
large number of studies have been performed, both in schizophrenia
and mood disorders. Globally, results are not so strong and universally
replicated to be applied in clinical practice; however, they are so
frequently reported that cannot be due to chance. In conclusion, gene
variants influence human behavior, liability to disorders and treatment
response. Many of them are supposed to do so in a subtle, interconnected
and environment modulated way. The final stage of
research will be an individualized profile of susceptibilities to be used
in clinical practice.
RS9.2.
GENETICS OF MOOD DISORDERS
N. Craddock
University of Cardiff, UK
The enormous public health importance of mood disorders, when
considered alongside their substantial heritability, has stimulated
much work, predominantly in bipolar disorder but increasingly also
in unipolar depression, aimed at identifying susceptibility genes using
both positional and functional molecular genetic approaches. The
advent of powerful molecular genetic tools, such as genome-wide
association studies of single nucleotide polymorphisms and measurement
of copy number variation, has made a major impact on understanding
of common non-psychiatric diseases and is starting to produce
replicable findings in psychiatric phenotypes, including mood
disorders. Very large samples (thousands or tens of thousands of samples)
are needed and, hence, collaborations are crucial. In bipolar disorder,
genes implicated at genome-wide levels of statistical significance
include CACNA1C and ANK3. The product of both genes is
involved in ion channel function, suggesting a key mechanism of
importance in the pathogenesis of bipolar disorder.
RS9.3.
GENETICS OF SCHIZOPHRENIA
M. Gennarelli
Department of Biomedical Sciences and Biotechnology,
University of Brescia, and Genetic Unit, IRCCS Fatebenefratelli,
Brescia, Italy
Schizophrenia is a neurodevelopment disorder with a strong genetic
component and the heritability was estimated approximately at 80%.
The current working hypothesis for genetic influences in schizophrenia
is the “common disease-common allele” model, in which the illness
is caused by a combination of common alleles, each contributing
a modest effect. On this basis, several candidate genes have been
identified, using linkage and association analysis approach in families
and case control studies in small samples of different ethnic groups.
However, replication in large samples and preliminary results of
genome-wide association studies fail to identify any specific risk variant.
These results are probably due to genetic heterogeneity. This is
confirmed, at least in part, by the recent identification of high prevalence
structural genome variants in sporadic cases of schizophrenia,
suggesting that rare “de novo” germline mutations contribute to disorder
susceptibility.
RS9.4.
GENETICS OF ANXIETY DISORDERS
K. Domschke
Department of Psychiatry, University of Muenster, Germany
Twin studies propose a strong genetic contribution to the pathogenesis
of panic disorder, with a heritability of about 48%. The present
paper provides an overview of results from linkage and cytogenetic
studies in panic disorder, and of association studies yielding support
for several candidate genes contributing to the genetic risk for panic
disorder, such as the adenosine A2A receptor, the catechol-O-methyltransferase
(COMT), the monoamine oxidase A (MAO-A) and the
serotonin receptor 1A (5-HT 1A
) genes. Additionally, evidence for a
gene-environment interaction between A2A variants and caffeine
consumption is presented. Finally, functional magnetic resonance
activation in brain regions critical for emotional and learning processes
has been proposed as a promising intermediate phenotype for
genetic studies in psychiatric disorders. Thus, applying an imaging
genetics approach, recent findings with respect to the genetic influence
of COMT and 5-HT 1A
variants on neuronal activation correlates
of emotional processing in panic disorder are reported.
RS10.
ARE WE WORKING WITH THE RIGHT CONCEPTS
IN ALZHEIMER’S DISEASE
RS10.1.
IS ALZHEIMER’S DISEASE A REAL DISEASE
ENTITY
I. Skoog
University of Gothenburg, Sweden
Since being described in 1907, Alzheimer’s disease has been characterised
by the presence of plaques and tangles and associated with a
profound memory and language disorder that leads to a progressive
dementia, loss of activities of daily living and death. It was initially
used to describe a dementia in younger patients, but for many years
now includes the more common late onset form which is said to
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