Although a variety of functional neuroimaging studies have used emotion
induction pdigms to investigate the neural basis of anger in control subjects,
no functional neuroimaging studies using anger induction have been conducted
in patient populations.
To study the neural basis of anger in unmedicated patients with major
depressive disorder with anger attacks (MDD + A), unmedicated patients with
MDD without anger attacks (MDD − A), and controls.
We used positron emission tomography, psychophysiologic measures, and
autobiographical narrative scripts in the context of an anger induction pdigm.
Academic medical center.
Thirty individuals, evenly divided among the 3 study groups.
In septe conditions, participants were exposed to anger and neutral
autobiographical scripts during the positron emission tomography study. Subjective
self-report and psychophysiologic data were also collected.
Main Outcome Measures
Voxelwise methods were used for analyses of regional cerebral blood
flow changes for the anger vs neutral contrast within and between groups.
Controls showed significantly (P<.001) greater
regional cerebral blood flow increases in the left ventromedial prefrontal
cortex during anger induction than patients with MDD + A, whereas these differences
were not present in other between-group analyses. Also, in controls, an inverse
relationship was demonstrated between regional cerebral blood flow changes
during anger induction in the left ventromedial prefrontal cortex and left
amygdala, whereas in patients with MDD + A there was a positive correlation
between these brain regions during anger induction. There was no significant
relationship between these brain regions during anger induction in patients
with MDD − A.
These results suggest a pathophysiology of MDD + A that is distinct
from that of MDD − A and that may be responsible for the unique clinical
presentation of patients with MDD + A.