Enhanced
amygdala volume in first depressive
episode
Changes
in amygdala volume have been observed in
patients with affective disorders. Increased
amygdala volume has been reported in
first-episode major depression patients compared
with age-matched healthy control subjects. The
study also compared amygdala volume in patients
with recurrent major depression and in
first-episode patients.
Thirty in-patients with first-episode major
depression and 27 in-patients with recurrent
major depression were recruited. All
subjects were aged 18-65 years and had received
antidepressive medication. Duration of illness
ranged from 1 month to 37 years. For comparison,
57 healthy control subjects, matched for age,
gender, and handedness, were also enrolled in
the study. Magnetic resonance imaging was used
to obtain brain images, particularly of the
amygdala.
Images analysis revealed enlarged amygdala
volume for patients with first-episode major
depression compared with patients with recurrent
major depression and healthy control subjects.
No differences were found between patients
suffering from recurrent depression and healthy
control subjects. Amygdala volume did not
correlate with age of onset, illness duration,
or severity of depression.
These results might be explained by a higher
neuronal activity in the amygdala coupled with
higher metabolism and higher cerebral blood flow
which might result in the greater amygdala
volume found in first-episode patients in
comparison with patients who have recurrent
major depression. In addition antidepressant
treatment might have an influence on amygdala
volume. Finally disease progression with
stress-related excitotoxic processes and reduced
neurotrophic factors during recurrent depressive
episodes cannot be ruled out, contributing to
decreased amygdala volume. Biol
Psychiatry 53: 338-344, 2003