Cerebral
blood flow remains abnormal in patients
recovered from depression
Brain
imaging studies have revealed that changes in
cerebral blood flow (CBF) which occur in
depression persist even in remitted patients.
These abnormalities may explain the
vulnerability to relapse in these recovered
patients and could represent a marker for
depression. The possible neural correlates of
such CBF changes and the sensitivity to
emotional stress have recently been
investigated.
Remitted unipolar depression patients,
individuals currently experiencing a depressive
episode and never-depressed volunteers were
studied before and after transient sad mood
challenge.
Positron emission tomography was used to measure
the changes in regional cerebral blood flow
after a temporary mood provocation of
memory-induced sadness consisting on recalling
an extremely sad personal experience such as
bereavement.
Regional CBF was decreased in the medial
orbitofrontal cortex by mood provocation in both
groups of depressed patients but not in healthy
controls. In remitted patients alone CBF
decreased in the pregenual anterior cingulate
while in healthy subjects an increase of CBF in
the subgenual cingulate and a decrease in right
prefrontal cortex were observed.
These results show that CBF in remitted
depression patients mirrors that of acutely
depressed subjects, however its pattern reveals
some distinct traits which make it specific to
this patient group. The mood challenge in
patients with remitted depression unmasks a
trait marker which may help understanding the
vulnerability of these individuals for relapse
and therefore may help to develop strategies to
prevent relapse of depression. Am
J Psychiat 159: 1830-1840, 2002