Table 2. Patient hippocampal volumes and subfields pre- and post-ECT, and HCs.
| Pre-ECT mean (s.d.) | Post-ECT mean (s.d.) | HC mean (s.d.) | Pre/post, t (P) | Effect sizes (Cohen's d) | |
|---|---|---|---|---|---|
| Intracranial volume | 1 464 016 (239527.6) | 1 446 838 (278450.4) | 1 492 612 (207348.7) | 1.3 (0.20) | 0.07 |
| Right hippocampus (mm3) | 37 478.0 (542.7) | 3892.7 (549.4) | 3961.30 (591.7) | −3.0 (0.009) | −0.27 |
| Right hippocampus (normalized) | 0.00260 (0.00045) | 0.00277 (0.00057) | 0.00268 (0.00041) | −2.7 (0.01) | −0.31 |
| Right CA1 (mm3) | 322.72 (41.2) | 332.46 (44.0) | 330.09 (41.2) | −2.6 (0.02) | −0.23 |
| Right CA2/3 (mm3) | 899.13 (145.7) | 948.34 (133.5) | 948.74 (138.0) | −4.1 (0.001) | −0.35 |
| Right dentate gyrus (mm3) | 508.72 (82.0) | 529.90 (73.7) | 528.93 (77.1) | −2.4 (0.03) | −0.27 |
| Right subiculum (mm3) | 583.22 (73.7) | 608.68 (83.8) | 617.94 (98.0) | −2.8 (0.01) | −0.32 |
| Left hippocampus (mm3) | 3738.56 (707.4) | 3797.8 (604.0) | 3938.75 (662.3) | −1.0 (0.32) | −0.09 |
| Normalized left hippocampus | 0.00258 (0.00046) | 0.00271 (0.00064) | 0.00266 (0.00047) | −1.5 (0.15) | −0.23 |
| Left CA1 (mm3) | 313.36 (46.7) | 315.45 (44.4) | 335.36 (46.8) | −0.3 (0.77) | −0.06 |
| Left CA2/3 (mm3) | 867.68 (152.1) | 897.07 (158.2) | 917.81 (167.7) | −2.6 (0.02) | −0.19 |
| Left dentate gyrus (mm3) | 492.10 (81.2) | 502.28 (77.6) | 517.41 (86.5) | −1.4 (0.18) | −0.12 |
| Left subiculum (mm3) | 586.59 (90.08) | 587.61 (93.15) | 615.32 (93.8) | −0.07 (0.94) | −0.01 |
Abbreviations: CA, cornu ammonis; ECT, electroconvulsive therapy; HC, healthy comparison.
The right hippocampus, right CA1, right CA2/3, right dentate gyrus and right subiculum increased in volume with ECT response. Left hippocampal volume increases were limited to CA2/3. The pre- and post-ECT/HC contrasts were not significant (P>0.10).