Abstract
Hippocampal dysfunction and structural abnormalities are commonly
found in Schizophrenia. They are evident in the first episode of illness
and have shown strong associations with functional outcome. However,
the biological origins and stability of these deficits over the illness course
remain unclear. One plausible hypothesis involves increased stress levels
and dysfunction of the central cerebral region responsible for its regulation,
the Hypothalamic-Pituitary-Adrenal (HPA) axis. Hippocampal function,
particularly the ability to remember new associations, is highly sensitive
to the neurotoxic effects of sustained increased cortisol levels. The aim
of the current study was to test the stability of hippocampal function in
drug-naı¨ve first-episode psychosis (FEP) patients over the first three
months of treatment, and test possible relationships with biological measures
of stress and HPA dysfunction. The performance of FEP patients and
normal controls (NC) were compared using a novel memory task that included
standard list learning and paired associated learning (PAL). At baseline,
FEP patients (n = 26) were significantly more impaired on a list
learning task than NC (n = 24) (P = .023), as well as on a hippocampal
PAL task (P = .027). Further, FEP patients showed greater impairment
on paired associates considered to be more abstract, which have been postulated to require greater hippocampal involvement. 12 FEP patients repeated
the assessment after 3 months of treatment with an alternate
form of the task, and showed a significant improvement in list learning performance that was not seen in NC (n = 18) (time X group interaction
P = .019). Conversely, FEP patients continued to be impaired on PAL
(P < .001) and there was no effect of or interaction with time (P =
.447). These findings suggest that hippocampal dysfunction is stable
over the first 3 months of treatment in first episode psychosis. Future analysis
to determine possible associations between these findings and biological
measures of stress and HPA axis activity (post-dexamethasone cortisol
levels and glucocorticoid receptor function) will be incorporated as a part of
this presentation.
Original language | English |
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Article number | 551121 |
Pages (from-to) | 297-297 |
Number of pages | 1 |
Journal | Schizophrenia Bulletin |
Volume | 35 |
Issue number | suppl. 1 |
DOIs | |
Publication status | Published - Mar 2009 |
Event | 12th International Congress on Schizophrenia Research - San Diego, United States Duration: 28 Mar 2009 → 1 Apr 2009 |