A Longitudinal Functional Magnetic Resonance Imaging Study of Verbal Working Memory in Depression After Antidepressant Therapy

doi:10.1016/j.biopsych.2006.12.022

Biological Psychiatry

Volume 62, Issue 11, 1 December 2007, Pages 1236-1243

https://doi.org/10.1016/j.biopsych.2006.12.022 Get rights and content

Background

Impairments in the neural circuitry of verbal working memory are evident in depression. Factors of task demand and depressive state might have significant effects on its functional neuroanatomy.

Methods

Two groups underwent functional magnetic resonance imaging while performing a verbal working memory task of varying cognitive load (n-back). The patient group comprised 20 medication-free individuals in an acute episode of unipolar major depression and the control group comprised 20 healthy individuals. Scans were acquired at weeks 0 (baseline), 2, and 8. Patients received treatment with fluoxetine after the baseline scan. Cerebral activations were measured for mean overall activation as well as the linear and quadratic load-response activity with increasing task demand (1-, 2-, 3-back).

Results

There were no significant differences in performance accuracy between groups. However, a main effect of group was observed in the load-response activity in frontal and posterior cortical regions within the verbal working memory network in which patients showed a greater load-response relative to control subjects. Group by time effects were revealed in the load-response activity in the caudate and thalamus. As a marker of treatment response, a lower linear load-response at baseline in the dorsal anterior cingulate, left middle frontal, and lateral temporal cortices was associated with an improved clinical outcome.

Conclusions

Maintenance of performance accuracy in patients was accompanied by a significant increase in the load-response activity in frontal and posterior cortical regions within the verbal working memory network. These data also provide further support for resilience of activity in the anterior cingulate as a predictor of treatment response in depression.

Section snippets

Participants

The MDD group consisted of dextral (Annett 1970) individuals meeting DSM-IV criteria for major depression (American Psychiatric Association 1994) by Structured Clinical Interview for DSM-IV (SCID) (First et al. 1995) and clinical interview with a consultant psychiatrist (AC or CF). Inclusion criteria were: an acute episode of unipolar major depression, and a minimum score of 18 on the 17-item Hamilton Rating Scale for Depression (HRSD) (Hamilton 1960). Exclusion criteria were: any history of

Behavioral Data

In the 0-back condition, there were neither significant main effects of time or group nor any interaction effects in response accuracy or reaction time. In the n-back task, performance accuracy showed a significant main effect of load [F(2,66) = 27.08, p < .001] with all participants making more errors at the higher loads and a main effect of time [F(2,66) = 3.58, p < .03] because all subjects showed an improved performance over time, but there was no significant main effect of group [F(1,33) =

Discussion

No significant differences in performance accuracy were observed between patients with depression and healthy individuals. The maintenance of adequate performance in patients was accompanied by a significant increase in the quadratic load-response activity in the left inferior frontal cortex relative to control subjects. No other prefrontal regions showed a significant difference between groups, although a main effect of group was also observed in posterior cortical and subcortical regions

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Original ArticleA Longitudinal Functional Magnetic Resonance Imaging Study of Verbal Working Memory in Depression After Antidepressant Therapy

Background

Methods

Results

Conclusions

Section snippets

Participants

Behavioral Data

Discussion

Acta Psychol (Amst)

Biol Psychiatry

Magn Reson Imaging

Neuroimage

Psychiatry Res Neuroim

Neuropsychologia

Biol Psychiatry

Neuroimage

Neuroimage

J Psychiatr Res

Neuroimage

J Affect Disord

J Psychiatr Res

Biol Psychiatry

J Affect Disord

Biol Psychiatry

J Affect Dis

Neuroimage

Biol Psychiatry

Psychiatry Res

Psychiatry Res

Diagnostic and Statistical Manual of Mental Disorders

A classification of hand preference by association analysis

Br J Psychol

Cognitive function in depression: A distinct pattern of frontal impairment in melancholia?

Psychol Med

Working Memory

Working memory: Looking back and looking forward

Nat Rev Neurosci

Changes in regional cerebral blood flow on recovery from depression

Psychol Med

Is the mechanism of prefrontal hypofunction in depression the same as in schizophrenia? Regional cerebral blood flow during cognitive activation

Br J Psychiatry

Deficits in hippocampal and anterior cingulate functioning during verbal declarative memory encoding in midlife major depression

Am J Psychiatry

Original Article
A Longitudinal Functional Magnetic Resonance Imaging Study of Verbal Working Memory in Depression After Antidepressant Therapy