TABLE 2.
Summary of the Studies Included in the Meta-Analyses of fMRI and EEG Studies of Reward Processing in Depression
| Characteristic | Overall | Subjects Under Age 18 |
Subjects Age 18 and Older |
|---|---|---|---|
| fMRI studies (N=38) | |||
| Sample composition | |||
| Depressed subjects compared with | |||
| healthy volunteers | |||
| Whole brain only | 15 | 1 | 14 |
| Whole brain and region of interest | 24 | 4 | 20 |
| Subjects at high risk of depression | |||
| compared with healthy volunteers | |||
| Whole brain only | 6 | 2 | 4 |
| Whole brain and region of interest | 10 | 5 | 5 |
| Depression on continuum | |||
| Whole brain only | 3 | 0 | 3 |
| Whole brain and region of interest | 8 | 3 | 5 |
| Overall | |||
| Whole brain onlya | 23 | 3 | 20 |
| Region of interest only | 15 | 7 | 8 |
| Reward types | |||
| Monetary | 32 | 9 | 23 |
| Primary | 2 | 1 | 1 |
| Affective | 3 | 3 | |
| Accuracy | 2 | 2 | |
| Tasks used | |||
| Monetary incentive delay task | 13 | 2 | 11 |
| Affective incentive delay task | 1 | 1 | |
| Decision making | 1 | 1 | |
| Wheel of fortune | 4 | 4 | |
| Card guessing | 7 | 6 | 1 |
| Reward learning | 4 | 4 | |
| Pavlovian prediction | 1 | 1 | |
| Effort expenditure for rewards task | 1 | 1 | |
| Modified reward task | 3 | 3 | |
| Primary reward task | 1 | 1 | |
| Reward guessing task | 1 | 1 | |
| Gambling task | 1 | 1 | |
| EEG studies (N = 12) | |||
| Sample composition | |||
| Depressed subjects compared with | 5 | 2 | 3 |
| healthy volunteers | |||
| Subjects with high risk of depression | 2 | 1 | 1 |
| compared with healthy volunteers | |||
| Depression on continuum | 5 | 3 | 2 |
| Reward types | |||
| Monetary | 11 | 5 | 6 |
| Points | 1 | 1 | |
| Tasks used | |||
| Doors guessing task | 7 | 4 | 3 |
| A gambling task | 3 | 3 | |
| A reward guessing task | 2 | 2 | |
a
Significant difference between groups, p<0.001.