Psy-World

Brain activation in the left prefrontal cortex remains impaired in remitted depressed patients in spite of their clinical improvement.

It has been reported that depressed patients showed attenuated activation in the left prefrontal cortex (PFC) during a verbal fluency task, when compared to control subjects. A study has investigated brain activation in patients with major depression who were in remission using the same activation paradigm. The study participants were 8 remitted major depressed patients (6 men, 2 women, aged 35-55 years) and 10 healthy volunteers (8 men, 2 women, aged 34-57 years). Patients had been in remission for 8.4 ± 3.3 days prior to the study. All the patients were medicated (4 patients received 200 mg fluvoxamine, and the other 4 received either 50 mg fluvoxamine, 150 mg clomipramine, 225 mg amoxapine, or 20 mg paroxetine). All the subjects were submitted to a verbal fluency task during which functional magnetic resonance imaging was carried out to study changes in cerebral blood oxygenation. There was no significant differences between the patients and the control subjects for verbal fluency performance. In both groups the verbal fluency task resulted in a significant activation of the left PFC. The control subject group also had significant activation in the cingulate cortex and thalamus, while the depressed group did not. Activiation in a small portion of the left PFC (middle frontal gyrus, Brodmann area 10) was significantly greater in the control group compared to the remitted depressed patients. Therefore, dysfunction in the left prefrontal cortex detected in depressed patients remains present during remission. Further studies are needed to replicate these findings with larger group of unmedicated subjects who had been in remission for a longer period of time. Okada G, Okamoto Y, Yamashita H, Ueda K, Takami H, Yamawaki S (2009). Attenuated prefrontal activation during a verbal fluency task in remitted major depression. Psychiatr Clin Neurosci 63:423-425. Updated June 2009