Objective: The treatment of geriatric depression is complicated by a variable and delayed response to antidepressant treatment. The present study was undertaken to test the hypothesis that combined total sleep deprivation and paroxetine treatment would produce a persistent reduction in glucose metabolism in the anterior cingulate cortex similar to that reported after long-term antidepressant treatment.
Method: Six elderly depressed patients who met the DSM-IV criteria for major depressive disorder and six age-matched comparison subjects underwent serial positron emission tomography (PET) studies at baseline, after total sleep deprivation, after recovery sleep (after the initial paroxetine dose), and after 2 weeks of paroxetine treatment (patients only). The PET data were analyzed by using statistical parametric mapping methods.
Results: The patients' scores on a 13-item version of the Hamilton Depression Rating Scale were decreased after total sleep deprivation, after recovery sleep, and after 2 weeks of treatment. The Hamilton depression scores of the comparison subjects were not significantly altered. In the patients, the greatest reductions in normalized, relative glucose metabolism after sleep deprivation were observed in the anterior cingulate cortex (Brodmann area 24), and they persisted after recovery sleep and antidepressant treatment. The comparison subjects demonstrated increased metabolism in these areas.
Conclusions: Improvement in the patients' depressive symptoms was accompanied by reduced glucose metabolism in the right anterior cingulate cortex and right medial frontal cortex. These preliminary data indicate that in elderly depressed patients, total sleep deprivation may accelerate the clinical and glucose metabolic response to antidepressant treatment.