Table 1. Demographics, clinical, neuroimaging, and neuropsychological measures.
| Whole group | Bipolar Disorder | Controls | Statistics | |
|---|---|---|---|---|
|
| ||||
| N = 39 | N = 27 | N = 12 | ||
| Age (years) | 68.2 (7.8) range = 52.6−83.2 | 68.6 (8.1) | 67.1 (7.4) | t(37) = 0.58, p = 0.57 |
| % female | 66.7 (n = 26) | 74.1 (n = 20) | 50.0 (n = 6) | Fisher's exact p = 0.16 |
| % Caucasian | 87.2 (n = 34) | 88.9 (n = 24) | 83.3 (n = 10) | Fisher's exact p = 0.63 |
| Education (years) | 15.1 (3.2) range = 9−20 | 15.0 (3.4) | 15.3(2.8) | t(37) =−0.33, p = 0.74 |
| Body mass index | 28.9 (4.7) range = 20.4−38.4 | 29.3 (4.9) range = 20.4−37.4 | 28.1 (4.2) range = 20.6−38.4 | t(37) = 0.78, p = 0.44 |
| % Bipolar type I (versus type II) | N/A | 85.2% (n = 23) | N/A | N/A |
| Duration of bipolar illness (years) | N/A | 44.8 (13.7) Median = 46 Range = 0.5−69 | N/A | N/A |
| Number of past psychiatric hospitalizations | N/A | 3.5 (4.2) Median = 2 Range = 0−15 | N/A | N/A |
| CIRS-G | ||||
| Total | 8.3 (4.7) range = 0−27 | 9.2 (5.3) | 6.3 (2.3) | t(37a) = 2.37, p = 0.02 |
| Count | 5.4 (2.4) range = 0−11 | 6.0 (2.5) | 4.1 (1.2) | t(36.5a) = 3.11, p = 0.004 |
| Heart + vascular | 1.9 (1.5) range = 0−6 | 1.8 (1.5) | 1.9 (1.6) | t(37) =−0.20, p = 0.85 |
| White matter hyperintensityb | 0.0007 (0.0006) range = 0.00002-0.003 | 0.0004 (0.0004) | 0.001 (0.001) | t(13.4a) = −3.57, p = 0.003 |
| Gray matter volume | ||||
| Total | 0.31 (0.07) range = 0.12−0.46 | 0.31 (0.07) | 0.31 (0.08) | t(37)=−0.12, p = 0.90 |
| Hippocampal | 0.006 (0.002) range = 0.003−0.009 | 0.006 (0.002) | 0.006 (0.002) | t(37) = 0.09, p = 0.93 |
| Neuropsychological Domainsc | ||||
| Global | −0.60 (0.87) range = −3.13 to1.21 | −0.88 (0.83) | 0.04 (0.60) | t(37)=−3.47, p = 0.001 |
| Speed/executive | −0.90 (1.24) range = −4.27 to 1.69 | −1.35(1.14) | 0.10(0.79) | t(37)=−3.98, p< 0.001 |
| Visual | −0.82 (1.44) range = −5.55 to 1.36 | −1.09(1.50) | −0.22(1.11) | t(37)=−1.80, p = 0.08 |
| Language | −0.19 (0.86) range = −2.65 to 1.26 | −0.34 (0.91) | 0.14(0.65) | t(37)=−1.64, p = 0.11 |
| Memory | −0.74 (1.13) range = −3.12 to 1.11 | −1.16(1.06) | 0.21 (0.58) | t(35.1a) =−5.23, p< 0.001 |
N/A, not applicable; CIRS-G, Cumulative Illness Rating Scale for Geriatrics.
a
Satterthwaite method reported because of unequal variances.
b
Means and standard deviation reported in the original units. Square root transformation used in analyses.
c
Neuropsychological domains same as in our group's previous paper (Gildengers et al. 2012)