Medial temporal lobe structures and hippocampal subfields in psychotic disorders: findings from the Bipolar-Schizophrenia Network on Intermediate Phenotypes (B-SNIP) study.
OBJECTIVE
Structural alterations in the hippocampus and other medial temporal lobe regions have been observed in schizophrenia. How these alterations and hippocampal subfields might differ across the psychosis spectrum remains unclear.


OBJECTIVE
To characterize medial temporal lobe structures, including hippocampal subfields, using magnetic resonance imaging and to examine their relation to psychosis and cognitive function across the psychosis spectrum.


METHODS
Case-control, cross-sectional neuroimaging study in a large series of probands with psychotic disorders and healthy volunteers as part of the Bipolar-Schizophrenia Network on Intermediate Phenotypes (B-SNIP). Patients with psychotic disorders (schizophrenia, n = 219; schizoaffective disorder, n = 142; and psychotic bipolar disorder, n = 188) and healthy controls (n = 337) were recruited across ambulatory clinics at university health centers in the B-SNIP consortium.


METHODS
Medial temporal lobe and hippocampal subfields were quantified with an automated parcellation approach using FreeSurfer software. Memory and other cognitive parameters were assessed using standardized neuropsychological tests.


RESULTS
Hippocampal volume reductions were seen in all 3 diagnostic groups when compared with healthy controls; alterations in the entorhinal cortex and parahippocampal regions were limited to schizophrenia and schizoaffective disorders (P < .001). Smaller volumes across the hippocampal subfields were seen in all 3 psychotic disorders, with the most prominent differences being in cornu ammonis 2/3 (P < .001). Hippocampal volumes were positively correlated with psychosis severity, declarative memory, and overall cognitive performance (P < .05).


CONCLUSIONS
Alterations in the hippocampus were evident across psychotic disorders. Hippocampal subfields that participate in memory-related processes supporting pattern separation and pattern completion might be abnormal and may underlie the pathophysiology of psychosis.
Department of Psychiatry, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts.
Ian
I
Mathew
Department of Psychiatry, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts.
Tova M
TM
Gardin
Department of Psychiatry, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts2Baylor College of Medicine, Houston, Texas.
Neeraj
N
Tandon
School of Social Work, University of Pittsburgh, Pittsburgh, Pennsylvania4Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania.
Shaun
S
Eack
Massachusetts General Hospital/Massachusetts Institute of Technology/Harvard Medical School Athinoula A. Martinos Center for Biomedical Imaging, Boston.
Alan N
AN
Francis
Department of Psychiatry, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts5Massachusetts General Hospital/Massachusetts Institute of Technology/Harvard Medical School Athinoula A. Martinos Center for Biomedical Imaging.
Larry J
LJ
Seidman
Department of Psychology, BioImaging Research Center, University of Georgia, Athens7Department of Neuroscience, BioImaging Research Center, University of Georgia, Athens.
Brett
B
Clementz
Olin Neuropsychiatry Research Center, Institute of Living, Hartford, Connecticut9Yale University School of Medicine, New Haven, Connecticut.
Godfrey D
GD
Pearlson
University of Texas Southwestern Medical Center, Dallas.
John A
JA
Sweeney
University of Texas Southwestern Medical Center, Dallas.
Carol A
CA
Tamminga
Department of Psychiatry, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts.
Matcheri S
MS
Keshavan
D000293:Adolescent; D000328:Adult; D000368:Aged; D001714:Bipolar Disorder / Q000175:diagnosis / Q000473:pathology* / Q000503:physiopathology; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D058068:Endophenotypes; D005260:Female; D006624:Hippocampus / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011618:Psychotic Disorders / Q000175:diagnosis / Q000473:pathology* / Q000503:physiopathology; D012559:Schizophrenia / Q000175:diagnosis / Q000473:pathology* / Q000503:physiopathology; D012720:Severity of Illness Index; D013702:Temporal Lobe / Q000473:pathology* / Q000503:physiopathology; D055815:Young Adult