Can response to partial sleep deprivation in depressed patients be predicted by regional changes of cerebral blood flow?

The possible predictive value of regional cerebral perfusion patterns with respect to the response to partial sleep deprivation (PSD) was evaluated in 15 major depressive patients (mean age = 54.9 years, mean Hamilton depression score = 21.6). Patients were studied with single photon emission computed tomography with technetium-99 m-D,L-hexamethyl-propylene amine oxime. Scans were performed on the morning before and after (at 08.00 h) PSD. Responders to PSD had significantly higher perfusion in the right orbitofrontal cortex than did non-responders before PSD. Multiple regression analysis indicated that right orbitofrontal/basal cingulate perfusion (r = -0.77, P < 0.001) before PSD, and left inferior temporal perfusion (r = 0.59, P = 0.01) after PSD, were fairly accurate predictors of change in Hamilton depression scores. Thus, it appears that the orbitofrontal cortex and the cingulate are involved in PSD and may serve as predictors of therapeutic response.