| Reference | Subjects(N) | Weeks off drug | Result |
| Pickar et al. (46) | SCZ (8) | 2 | r = 0.82 |
| Davis et al. (61) | SCZ (18) | 4 | r = 0.66 |
| Pickar et al. (56) | SCZ (11) | 5 | r = 0.81 |
| Davidson and Davis (62) | SCZ (14), NC (14) | 3 | pHVA SCZ < NC |
| Kirch et al. (63) | SCZ (22) | 6 | ns |
| Maas et al. (96) | SCZ (23) | 2 | r = 0.38 |
| Sharma et al. (47) | SCZ (11) PSYCHOT (6) |
2.5 | r = -0.08 |
| Van Putten et al. (53) | SCZ (22) | 4 | ns |
| Markianos et al. (97) | SCZ (0) | Neuroleptic-naive ns | ns |
aAbbreviations are defined in footnote a of Table 1.
published 2000