Quantitative MRI of the hippocampus and amygdala in severe depression.
BACKGROUND
There is little evidence to support possible structural changes in the amygdala and hippocampus of patients with severe depression.


METHODS
Quantitative MRI of the amygdala and hippocampus, as well as proton spectroscopy (MRS) of mesial temporal structures were studied in 34 drug-resistant in-patients with major depression and compared with 17 age-matched controls. Volumetric MRI data were normalized for brain size.


RESULTS
The volume of the left hippocampus was significantly smaller in the patients compared with the controls. Both groups exhibited similar significant hippocampal asymmetry (left smaller than right). The patients, but not the controls, had significant asymmetry of the amygdalar volumes (right smaller than left). No differences were observed between the patients and controls in the T2 relaxation times for the hippocampus and amygdala. Mesial temporal lobe MRS revealed a significantly elevated choline/creatine ratio in the patients compared with the controls.


CONCLUSIONS
This quantitative MRI study provides support for a possible association between structural and biochemical substrates and severe drug-resistant major depression.
Mervaala
E
E
Department of Clinical Neurophysiology, University Hospital of Kuopio, Finland.
Föhr
J
J
Könönen
M
M
Valkonen-Korhonen
M
M
Vainio
P
P
Partanen
K
K
Partanen
J
J
Tiihonen
J
J
Viinamäki
H
H
Karjalainen
A K
AK
Lehtonen
J
J
D000328:Adult; D000679:Amygdala / Q000473:pathology*; D000928:Antidepressive Agents / Q000494:pharmacology; D016022:Case-Control Studies; D003866:Depressive Disorder / Q000473:pathology*; D004351:Drug Resistance; D005260:Female; D007839:Functional Laterality; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged
D000928:Antidepressive Agents