Table 1.
Clinical, Cognitive, and PET Characteristics Before and After Dose Reduction
| Characteristic | N (%) | Paired Samples t test (df) | P |
|---|---|---|---|
| Gender Female, N (%) | 11 (24.3%) | NA | NA |
| Diagnosis, N (%) | |||
| Schizophrenia | 31 (83.8%) | ||
| Schizoaffective disorder | 6 (16.2%) | ||
| Antipsychotic, N (%): | NA | NA | |
| Olanzapine | 22 (59.5%) | ||
| Risperidone | 15 (40.5%) | ||
| Mean (SD) | |||
| Age, years (range: 50–79, N = 37) | 60.2 (7.0) | NA | NA |
| Age, years (range: 50–59, N = 17) | 54.0 (3.2) | ||
| Age, years (range: 60–64), N = 7) | 61.6 (1.4) | ||
| Age, years (range: 60–64), N = 13) | 67.7 (4.1) | ||
| Dose, mg/day: | |||
| Olanzapine – Before | 20.9 (6.9) | 13.3 (21) | 0.001 |
| Olanzapine – After | 13.5 (4.4) | ||
| Risperidone – Before | 4.5 (2.6) | 6.0 (14) | 0.001 |
| Risperidone – After | 2.9 (1.6) | ||
| CPZE, mg/day: | |||
| Before | 355.4 (164.0) | 231.1 (104.2) | 0.001 |
| After | 12.27 (36) | ||
| PANSS Total Score: | |||
| Before | 59.7 (14.1) | 2.46 (36) | 0.019* |
| After | 58.8 (14.2) | ||
| Whole Striatum BPND: | |||
| Before | 1.06 (0.35) | −4.85 (36) | 0.001 |
| After | 1.31 (0.40) | ||
| Immediate Memory: | |||
| Before | 83.6 (18.6) | −1.44 (36) | 0.16 |
| After | 86.1 (17.8) | ||
| Visuospatial/Constructional: | |||
| Before | 73.1 (11.5) | −1.66 (36) | 0.11 |
| After | 75.8 (12.0) | ||
| Language: | |||
| Before | 87.2 (8.8) | 0.36 (36) | 0.72 |
| After | 86.5 (12.6) | ||
| Attention: | |||
| Before | 83.5 (15.1) | −0.80 (35) | 0.43 |
| After | 84.8 (17.0) | ||
| Delayed Memory: | |||
| Before | 77.4 (19.5) | −0.70 (36) | 0.49 |
| After | 79.1 (18.6) | ||
| RBANS Total Scale: | |||
| Before | 76.0 (12.3) | −1.54 (35) | 0.13 |
| After | 77.9 (14.8) | ||
BPND = non-displaceable Binding Potential; CPZE = Chlorpromazine Equivalence; PANSS = Positive And Negative Syndrome Scale; RBANS = Repeatable Battery for the Assessment of Neuropsychological Status.
*
not significant after Bonferroni correction; SD = Standard Deviation