Project Details
Abstract
Psychosis is an etiologically complex syndrome that arises from the interaction of a
range of factors. The most commonly studied disorder regarding constitutional vulnerability
to psychosis is schizophrenia. Two major theories of schizophrenia are respectively, the
dopamine hypothesis and the neurodevelopmental hypothesis. The classical
neurodevelopmental hypothesis has been recently modified to include the pathogenic effects
of psychostimulants and cannabis abuse. Methamphetamine (MAMP) use has been reported
to result in psychotic symptoms lasting more than several months. The prolonged psychotic
symptoms in MAMP psychosis are hypothesized by some investigators to generally represent
a triggering or unmasking of vulnerability to a psychotic state or latent schizophrenia. In the
past 10 years, we have conducted a series of studies that investigated predisposing factors to
MAMP-induced psychosis. By this study, we have published a series of reports describing our
findings in clinical characteristics, premorbid characteristics, familial psychosis morbid risks
and genetic associations among MAMP abusers, and established collaborations internationally
with several research groups. Our studies showed that the relatives of MAMP users with a
lifetime diagnosis ofMAMP psychosis had a significantly higher morbid risk for schizophrenia
than the relatives of those probands who never became psychotic. Furthermore, the morbid risk
for schizophrenia in the relatives of the subjects with a prolongedMAMP psychosis was higher
than in the relatives of those users with a brief MAMP psychosis. Compared to those MAMP
abusers without psychosis, the MAMP abusers with psychosis had significantly more
premorbid schizoid/schizotypal personality trait. Our previous work on MAMP psychosis has
been frequently cited in research papers and review articles, and has been suggested to be
influential in the fields of comorbidity of substance abuse, etiological models of
schizophrenia, and the nosology of prolonged or chronic substance-induced psychosis.
However, the issue of a prolonged drug-induced psychosis continues to remain a contentious
issue. This proposed study will be the largest longitudinal study of prolonged MAMP-induced
psychosis, and will be the largest study that compares this group of patients with carefully
matched schizophrenics.
The aims of this investigation are 1) to understand the role of substance use in the
development of chronic psychotic disorders, and its interaction with genes, family morbid
risks for psychosis and premorbid function; 2) to characterize clinical presentations of
MAMP-induced chronic psychosis, including psychotic dimensions and neurocognitive
performance. We aim to longitudinally follow up 100 cases with chronic psychosis after
MAMP use recruited previously since 10 years ago. We will characterize their clinical
presentations and investigate their predisposing factors by comparing to 100 patients with
schizophrenia or schizoaffective disorder after matching in age, sex, subtype of psychosis and
duration of psychosis. We will compare the neurocognitive performance using the Brief
Assessment of Cognition in Schizophrenia between these two groups. We will also compare
genetic polymorphisms of susceptibility genes that have recently been reported to be
associated with schizophrenia, such as neuregulin, dysbindin, Disrupted in Schizophrenia 1
(DISC1) and catechol-O-methyltransferase (COMT) genes between these two groups and 200
MAMP abusers without psychosis which were collected in our previous studies.
Project IDs
Project ID:PC9902-1663
External Project ID:NSC98-2314-B182-023-MY3
External Project ID:NSC98-2314-B182-023-MY3
Status | Finished |
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Effective start/end date | 01/08/10 → 31/07/11 |
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