Depression is very common in multiple sclerosis
(MS) but the underlying biological mechanisms are poorly understood.
The hippocampus plays a key role in mood regulation and is implicated in
the pathogenesis of depression. This study utilizes volumetric and
shape analyses of the hippocampus to characterize neuroanatomical
correlates of depression in MS.
A cross-section of 109 female patients
with MS was evaluated. Bilateral hippocampi were segmented from MRI
scans (volumetric T(1) -weighted, 1 mm(3) ) using automated tools. Shape
analysis was performed using surface mesh modeling. Depression was
assessed using the Center for Epidemiologic Studies-Depression (CES-D)
scale. Eighty-three subjects were classified as low depression (CES-D
0-20) versus 26 subjects with high depression (CES-D ≥ 21). Right
hippocampal volumes (P = 0.04) were smaller in the high depression
versus the low depression groups, but there was no significant
difference in left hippocampal volumes. Surface rendering analysis
revealed that hippocampal shape changes in depressed patients with MS
were clustered in the right hippocampus. Significant associations were
found between right hippocampal shape and affective symptoms but not
vegetative symptoms of depression. Our results suggested that regionally
clustered reductions in hippocampal thickness can be detected by
automated surface mesh modeling and may be a biological substrate of MS
depression in female patients
The hippocampus
(after the shape of a seahorse) is the site of memory formation there
are two on on the left and one on the right of the brain. This study
suggests that the right hippocampus is smaller in more depressed MSers.
This was associated with affective symptoms, which are mood and
emotions, rather than vegetative (sleep eating etc). The levels of
significant differences was small. This study suggests that the size of the hippocampus may influence depression.
Labels: Depression, hippocampus