Lithium may be neuroprotective in BD patients
MedWire News: Study results suggest that lithium treatment may have a neuroprotective effect in patients with bipolar disorder (BD).
Writing in Bipolar Disorders, Tomas Hajek (Dalhousie University, Halifax, Nova Scotia, Canada) and team explain: "Hippocampal volume decrease secondary to illness burden is among the most replicated neuroimaging findings in unipolar depression.
"It is thus surprising that the majority of studies showed comparable or even larger hippocampal volumes in BD patients relative to healthy controls."
They hypothesized that this "may reflect neuroprotective effects of lithium."
To investigate, the team studied 17 BD patients (mean age 47.8 years) who had been treated with lithium for at least 2 years (lithium group), 12 BD patients (mean age 45.6 years) who had less than 3 months' lifetime exposure to lithium (non-lithium group), and 11 mentally healthy controls (mean age 46.0 years).
A second group of young (aged 15-30 years) lithium-naïve BD patients and 18 gender- and age-matched controls were also recruited.
All of the participants underwent magnetic resonance imaging scans and voxel-based morphometry was used to measure hippocampal volumes.
Analysis revealed that patients in the non-lithium group had significantly reduced left hippocampal gray matter volume compared with controls, with a trend towards reduced hippocampal gray matter volume compared with the lithium group.
There was no significant difference in hippocampal volume between patients in the lithium group and controls.
The researchers also found that there were no significant hippocampal gray-matter volume differences between the young lithium-naïve BD patients and controls.
The researchers conclude: "These results provide indirect support for neuroprotective effects of lithium and negative effects of illness burden on hippocampal volumes in BD."
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By Mark Cowen