Correlations between fMRI activation and individual psychotic symptoms in un-medicated subjects at high genetic risk of schizophrenia.
BACKGROUND
It has been proposed that different types of psychopathology in schizophrenia may reflect distinguishable pathological processes. In the current study we aimed to address such associations in the absence of confounders such as medication and disease chronicity by examining specific relationships between fMRI activation and individual symptom severity scores in un-medicated subjects at high genetic risk of schizophrenia.


METHODS
Associations were examined across two functional imaging paradigms: the Hayling sentence completion task, and an encoding/retrieval task, comprising encoding (at word classification) and retrieval (old word/new word judgement). Symptom severity was assessed using the positive and negative syndrome scale (PANSS). Items examined were hallucinations, delusions, and suspiciousness/persecution.


RESULTS
Associations were seen in the anterior middle temporal gyrus in relation to hallucination scores during the sentence completion task, and in the medial temporal lobe in association with suspiciousness/persecution scores in the encoding/retrieval task. Cerebellar activation was associated with delusions and suspiciousness/persecution scores across both tasks with differing patterns of laterality.


CONCLUSIONS
These results support a role for the lateral temporal cortex in hallucinations and medial temporal lobe in positive psychotic symptoms. They also highlight the potential role of the cerebellum in the formation of delusions. That the current results are seen in un-medicated high risk subjects indicates these associations are not specific to the established illness and are not related to medication effects.
Whalley
Heather C
HC
Division of Psychiatry, School of Molecular and Clinical Medicine, University of Edinburgh, Edinburgh, Scotland, UK. hwhalley@staffmail.ed.ac.uk
Gountouna
Viktoria-Eleni
VE
Hall
Jeremy
J
McIntosh
Andrew
A
Whyte
Marie-Claire
MC
Simonotto
Enrico
E
Job
Dominic E
DE
Owens
David G C
DG
Johnstone
Eve C
EC
Lawrie
Stephen M
SM
D000293:Adolescent; D000328:Adult; D001479:Basal Ganglia / Q000503:physiopathology; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D002531:Cerebellum / Q000503:physiopathology; D003469:Culture; D003702:Delusions / Q000175:diagnosis / Q000235:genetics* / Q000503:physiopathology* / Q000523:psychology; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006212:Hallucinations / Q000175:diagnosis / Q000235:genetics* / Q000503:physiopathology* / Q000523:psychology; D006624:Hippocampus / Q000503:physiopathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D011939:Mental Recall / Q000502:physiology; D009483:Neuropsychological Tests / Q000706:statistics & numerical data*; D010296:Parietal Lobe / Q000503:physiopathology; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data*; D011594:Psychometrics; D011597:Psychomotor Performance / Q000502:physiology; D012307:Risk Factors; D012559:Schizophrenia / Q000175:diagnosis / Q000235:genetics* / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D013223:Statistics as Topic; D013702:Temporal Lobe / Q000503:physiopathology; D013788:Thalamus / Q000503:physiopathology; D014706:Verbal Learning / Q000502:physiology; D014936:Word Association Tests