Table 1.
Subgroup analysis on stimulation settings (target and frequency, method of localization, number of sessions (single versus multiple)) for stimulant (nicotine, cocaine, methamphetamine) and behavioral (eating disorder, gambling disorder) groups (k = 20).
| Effect Size | Heterogeneity | ||||||
|---|---|---|---|---|---|---|---|
| k * | Hedge’s g
(Random Effect) |
CI 95% | Z-Statistic | p | p | I 2 | |
| Target and frequency | |||||||
| HF Left DLPFC | 12 | −0.396 | −0.603; −0.190 | 3.76 | <0.001 | 0.656 | 0 |
| LF Left DLPFC | 1 | −0.670 | −1.142; −0.198 | 2.78 | <0.001 | - | - |
| LF Right DLPFC | 3 | −0.120 | −0.488; 0.249 | 0.64 | 0.524 | 0.637 | 0 |
| HF MPFC | 1 | −0.781 | −1.744; 0.182 | 1.59 | 0.112 | - | - |
| LF MPFC | 2 | −0.108 | −0.570; 0.355 | 0.46 | 0.648 | 0.976 | 0 |
| LF SFG | 1 | −0.175 | −0.892; 0.542 | 0.48 | 0.633 | - | - |
| Method of localization | |||||||
| No neuronavigation | 14 | −0.352 | −0.531; −0.173 | 3.86 | <0.001 | 0.678 | 0 |
| Neuronavigation | 6 | −0.328 | −0.620; −0.037 | 2.21 | 0.027 | 0.436 | 0 |
| Number of sessions | |||||||
| Single | 14 | −0.354 | −0.540; −0.169 | 3.74 | <0.001 | 0.934 | 0 |
| Multiple | 6 | −0.321 | −0.687; 0.045 | 1.72 | 0.086 | 0.121 | 42.6 |
* Units of analysis: DLPFC, dorsolateral prefrontal cortex; MPFC, medial prefrontal cortex; SFG, superior frontal gyrus; HF, high frequency; LF, low frequency.