Table 3.
Comparison of demographic, neuropsychological variables and normalized fMRI signal change (2-back WM > 0- back task contrast) in controls (CON) vs. a sub-sample of 10 unmedicated persons with bipolar disorder (BD) who were part of the original sample of BD (n=19).
| Variable | Con (n=19) | Unmed BD (n=10) | Con v. Unmed BD |
|---|---|---|---|
| Matching variables | Mean (SD) or % | Mean (SD) or % | t (p) or X2 (p) |
| Age at MRI | 39.2 (2.7) | 41.7 (2.9) | 2.20 (.04)* |
| Gender (% Male) | 47.4% | 60.0% | .42 (.7) |
| Ethnicity (% Cauc.) | 94.7% | 70.0% | 3.93 (.08) |
| Handedness (% R) | 84.2% | 80.0% | .97 (.62) |
| Parental Education yrs | 14.2 (3.0) | 13.3 (3.0) | .59 (.56) |
| WRAT-3a Reading | 103.5 (8.7) | 97.7 (11.8) | 1.30 (.20) |
|
| |||
| Education & IQ | |||
| Education (years) | 15.3 (2.5) | 13.2 (1.4) | 2.28 (.03)* |
| IQ estimateb | 110.6 (13.3) | 101.4 (10.9) | 1.53 (.13) |
|
| |||
| In Scanner tasks
| |||
| 0-back % correct | 98.7 (1.7) | 96.8 (4.9) | 1.47 (.15) |
| 0-back reaction timec | 560 (60) | 570 (80) | .56 (.58) |
| 2-back % correct | 89.9 (6.2) | 81.3 (9.5) | 2.94 (.007)* |
| 2-back reaction timec | 810 (130) | 850 (160) | .93 (.36) |
|
| |||
| POMS Mood scores
| |||
| Tension/Anxiety | 33.2 (6.0) | 37.8 (7.7) | 1.69 (0.10) |
| Depression | 37.9 (6.6) | 40.4 (6.9) | 0.92 (0.37) |
| Anger/Hostility | 44.2 (7.7) | 46.6 (7.2) | 0.78 (0.44) |
| Vigor | 63.2 (10.3) | 60.2 (6.6) | 0.80 (0.43) |
| Fatigue | 44.8 (7.1) | 47.3 (5.3) | 0.95 (0.35) |
| Confusion | 34.4 (5.4) | 39.7 (6.1) | 2.31 (0.03)* |
|
| |||
| Substance use
| |||
| Recent alcohol used,e | .16 (.37) | 2.30 (2.79) | 2.42(.04)* |
| Lifetime alcohol usef | .95 (.78) | 1.80 (1.14) | 2.39(.02)* |
| Lifetime drug usef | .74 (.87) | 1.20 (1.40) | 1.10 (.28) |
| fMRI signal change | (x, y, z)g | Effect size | th (p-value) |
|
| |||
| Anterior Insula (BA 13)
| |||
| Unmed BD > Con | −36, 0, 15 | 2.00 | 5.20 (.045)i |
|
| |||
| Frontopolar Cx. (BA 10) | |||
| Con > Unmed BD | −27, 57, 21 | 1.07 | 2.77 (.13)i |
| Rel > Unmed BD | −27, 57, 21 | 1.21 | 3.15 (.08)i |
WRAT-R, Wide Range Achievement Test-Revised (Jastak & Jastak, 1985).
IQ estimate derived from vocabulary and block design age-scaled scores of the Wechsler Adult Intelligence Scale-Revised (Wechsler, 1981).
milliseconds
Number of alcoholic beverages consumed on the day prior to scanning.
Levene’s Test for Equality of Variances was significant, therefore equality of variances was not assumed.
Interviewer ratings from the Structured Clinical Interview for DSM-IV (SCID) (First et al. 1996) which assesses the abuse and/or dependence on both illicit drugs and prescribed medications (when not being used as prescribed). Examples of drugs assessed include cannabis, sedatives/hyponotics/anxiolytics, stimulants, opiods, cocaine, and hallucinogens/PCP).
MNI: Montreal Neurological Institute Coordinate System.
Maximum voxel-wise t-value within the cluster of interest.
Small volume correction method was used to correct the cluster-wise statistic (p < .05).
Significance level, p< .05.