25. 9. 2008
Regular Symposia
XI V WORLD CON GRES OF PSY CHIATRY
DISCRETE AND CONTINUOUS APPROACH IN THE
CONCEPTUALIZATION OF PSYCHOSES
INSTITUTIONS
1. Charles University, Psychiatry, Prague, Czech Republic
AUTHORS
1. Cyril Hoschl1, Dr., MD, milevr@providencecare.ca
The diagnostic distinction of bipolar affective disorder and schizophrenia
in current classification systems ICD-10 and DSM IV is
based on Kraepelin‘s definition of „dementia praecox“ and „maniodepressive
psychosis“. However, the validity of the diagnostic distinction
is challenged by various independent findings. The authors
review the similarities and distinctions between both disorders in
a range from psychopathology to neuroimaging methods with an
emphasis on genetic findings as a major source of evidence of an
overlap between bipolar disorder and schizophrenia.
Both bipolar disorder and schizophrenia demonstrate several similar
psychopathological and epidemiologic characteristics. Both disorders
are strongly influenced by genetic factors: results of linkage
studies show a partial overlap of susceptibility loci. Two relatively
common chromosomal aberrations are associated with both bipolar
disorder and schizophrenia. Association studies of candidate genes
in either disorder identified several genes involved in both disorders,
such as NRG1, DISC1, and G72/G30. Emerging gene functions
possibly involved in both disorders include neurogenesis, synaptogenesis,
myelinization, and neurotransmition. Bipolar disorder and
schizophrenia also demonstrate some similarities in neurotransmitter
dysfunction and share some, but not all, pharmacological mechanisms.
Cognitive impairment in schizophrenia is well established
during acute episodes as well as during remission and is more
obvious compared to bipolar disorder. Moreover, children who developed
schizophrenia in adulthood are characterised by cognitive,
social, emotional, and behavioral impairments, in contrast to an
impairment of a lesser degree found in children who later developed
bipolar disorder. Also, patients with schizophrenia have more extensive
structural brain abnormalities than those with bipolar disorder.