Study Report
Reference
Citation | Epstein, 2006 PubMed |
Full Info | Epstein, J., Pan, H., Kocsis, J.H., Yang, Y., Butler, T., Chusid, J., Hochberg, H., Murrough, J., Strohmayer, E., Stern, E. et al. (2006) Lack of ventral striatal response to positive stimuli in depressed versus normal subjects. Am J Psychiatry, 163, 1784-1790.
|
Study
Hypothesis or Background |
Most of the functional neuroimaging studies of depression have focused primarily on the resting state or responses to negatively valenced stimuli. However, depression consists not only of an accentuation of negative affective processing but of an inability to experience pleasure or positive motivation. The authors tested the hypothesis that depressed subjects would show less activation than healthy comparison subjects, in response to positive stimuli, in ventral striatal regions associated with processing of reward and positive stimuli.
|
Sample Information | 10 unmedicated depressed patients (9 women and 1 man; mean age=35.6 years; 8 right-handed, 2 left-handed) and 12 normal controls (7 women and 5 men; mean age=32.0 years; all right-handed) |
Method Detail | Positive, negative, and neutral words were presented to 10 unmedicated depressed patients and 12 healthy comparison subjects in the context of a 3T functional magnetic resonance imaging (MRI) paradigm. Image processing and analysis were performed using statistical parametric mapping with a mixed-effects model. Significant differences in neural responses were assessed, examining group, condition, and interaction effects of interest within the context of a general linear model. |
Method Keywords | functional magnetic resonance imaging (fMRI) |
Result | Relative to comparison subjects, depressed patients demonstrated significantly less bilateral ventral striatal activation to positive stimuli, correlating with decreased interest/pleasure in and performance of activities. They also displayed decreased activation to positive stimuli in a dorsomedial frontal region associated with processing of self-related stimuli. Responses of depressed subjects to negative stimuli were consistent with the growing literature on frontolimbic dysfunction in depression. |
Conclusions | This finding 1) supports a pathophysiological model of depression that includes reward/motivational pathway dysfunction, 2) suggests a contributing neural substrate of the inability to experience pleasure or engage in rewarding activities, 3) provides greater specification of abnormalities of basal ganglia function in depression, and 4) may help guide treatment approaches. |
Relationships reported by
Epstein, 2006
Component A Approved Name (Name in Paper) |
Component A Type |
Component B Approved Name (Name in Paper) |
Component B Type |
Statistical Result |
Relationship Description |
Result Category (Positive/Negative)) |
MDD
|
syndrome |
dorsomedial prefrontal cortex (DMPFC) (dorsomedial frontal region) |
brain morphology and function |
|
Relative to comparison subjects, depressed patients displayed decreased activation to positive stimuli in a dorsomedial frontal region associated with processing of self-related stimuli. |
Positive
|
MDD
|
syndrome |
Reward system (brain reward system) |
brain morphology and function |
|
This finding supports a pathophysiological model of depression that includes reward/motivational pathway dysfunction. |
Positive
|
Anhedonia (anhedonia)
|
symptoms |
Ventral striatum (ventral striatum) |
brain morphology and function |
|
Relative to comparison subjects, depressed patients demonstrated significantly less bilateral ventral striatal activation to positive stimuli, correlating with decreased interest/pleasure in and performance of activities. |
Positive
|
MDD
|
syndrome |
Ventral striatum (ventral striatum) |
brain morphology and function |
|
Relative to comparison subjects, depressed patients demonstrated significantly less bilateral ventral striatal activation to positive stimuli. |
Positive
|