A quantitative magnetic resonance imaging study of regional brain T1
spin-lattice relaxation times in 29 normal volunteers and in 20 patients
with major depression revealed significantly shortened T1 relaxation times
for the hippocampus in depressed patients. These differences were
particularly prominent in elderly depressed patients. T1 relaxation times
are reflective of the content and macromolecular environment of tissue
water protons; shorter hippocampal T1 values may reflect differences in the
content or organizational properties of hippocampal water protons. These
findings are consistent with several lines of evidence that have implicated
a role for the hippocampus in the regulation of mood and in the
pathophysiology of the stress response, and they suggest that major
depression may be associated with biophysical tissue changes in the aging
hippocampus.Abstract Teaser