Prediction of functional outcome 18 months after a first psychotic episode: a proton magnetic resonance spectroscopy study.
BACKGROUND
Recent magnetic resonance imaging studies have attempted to relate volumetric brain measurements in early schizophrenia to clinical and functional outcome some years later. These studies have generally been negative, perhaps because gray and white matter volumes inaccurately assess the underlying dysfunction that might be predictive of outcome.


OBJECTIVE
To investigate the predictive value of frontal and temporal spectroscopy measures for outcome in patients with first-episode psychoses.


METHODS
Left prefrontal cortex and left mediotemporal lobe voxels were assessed using proton magnetic resonance spectroscopy to provide the ratio of N-acetylaspartate (NAA) and choline-containing compounds to creatine and phosphocreatine (Cr) (NAA/Cr ratio). These data were used to predict outcome at 18 months after admission, as assessed by a systematic medical record audit.


METHODS
Early psychosis clinic.


METHODS
Forty-six patients with first-episode psychosis.


METHODS
We used regression models that included age at imaging and duration of untreated psychosis to predict outcome scores on the Global Assessment of Functioning Scale, Clinical Global Impression scales, and Social and Occupational Functional Assessment Scale, as well as the number of admissions during the treatment period. We then further considered the contributions of premorbid function and baseline level of negative symptoms.


RESULTS
The only spectroscopic predictor of outcome was the NAA/Cr ratio in the prefrontal cortex. Low scores on this variable were related to poorer outcome on all measures. In addition, the frontal NAA/Cr ratio explained 17% to 30% of the variance in outcome.


CONCLUSIONS
Prefrontal neuronal dysfunction is an inconsistent feature of early psychosis; rather, it is an early marker of poor prognosis across the first years of illness. The extent to which this can be used to guide treatment and whether it predicts outcome some years after first presentation are questions for further research.
Wood
Stephen J
SJ
Melbourne Neuropsychiatry Centre, University of Melbourne, c/o National Neuroscience Facility, 161 Barry Street, Carlton, Melbourne, Victoria 3053, Australia. sjwood@unimelb.edu.au
Berger
Gregor E
GE
Lambert
Martin
M
Conus
Phillipe
P
Velakoulis
Dennis
D
Stuart
Geoffrey W
GW
Desmond
Patricia
P
McGorry
Patrick D
PD
Pantelis
Christos
C
D000328:Adult; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism*; D005260:Female; D005500:Follow-Up Studies; D007839:Functional Laterality; D006624:Hippocampus / Q000378:metabolism; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000706:statistics & numerical data*; D008297:Male; D017063:Outcome Assessment, Health Care; D010359:Patient Readmission; D010725:Phosphocreatine / Q000378:metabolism; D011237:Predictive Value of Tests; D017397:Prefrontal Cortex / Q000378:metabolism*; D011379:Prognosis; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D011618:Psychotic Disorders / Q000175:diagnosis* / Q000378:metabolism; D012559:Schizophrenia / Q000175:diagnosis / Q000378:metabolism; D013702:Temporal Lobe / Q000378:metabolism*
D010725:Phosphocreatine; D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline