Objective: The variable speed and durability of response to antidepressant medications in geriatric depression is a significant clinical problem. The authors evaluated changes in cerebral glucose metabolism measured with positron emission tomography (PET) during a clinical trial designed to accelerate medication response by the use of one night of total sleep deprivation (TSD), and they asked whether changes would correlate with treatment outcome after 12 weeks of antidepressant treatment.
Methods: Twelve elderly, unipolar depressed patients underwent serial PET studies at baseline, post-TSD, post-recovery sleep (after an initial paroxetine dose), and after 2 weeks of paroxetine treatment.
Results: Decreased regional glucose metabolism after TSD, recovery sleep, and 2 weeks of treatment was associated with clinical improvement at 12 weeks. The right cingulate gyrus area was consistently correlated with clinical improvement across treatment conditions.
Conclusion: These data indicate that the early metabolic alterations in the right cingulate gyrus and the persistence of these adaptive changes are associated with improvement in depressive symptoms.