TABLE 1. Demographic and Clinical Characteristics for Healthy Comparison Subjects, Bipolar I Patients, and Bipolar II Patients in a Study of Ventral Striatum Activity.
| Characteristica | Healthy Comparison Subjects (N=20) | Bipolar I Patients (N=17) | Bipolar II Patients (N=15) | |||
|---|---|---|---|---|---|---|
| Mean | SD | Mean | SD | Mean | SD | |
| Age (years) | 42.30 | 5.99 | 42.82 | 7.31 | 40.53 | 8.09 |
| IQ | 115.73 | 7.73 | 114.52 | 8.02 | 113.10 | 6.91 |
| Hamilton Depression Rating Scale score | 0.60b | 0.94 | 3.88 | 3.87 | 2.67 | 2.94 |
| Young Mania Rating Scale score | 0.65b | 0.93 | 3.17 | 2.32 | 1.80 | 2.80 |
| Hypomania Checklist–32 score | 23.73 | 5.99 | 23.13 | 4.82 | ||
| Age at first mood episode (years) | 17.57 | 5.41 | 18.92 | 7.63 | ||
| Age at bipolar diagnosis (years) | 27.06 | 6.43 | 31.00 | 10.05 | ||
| Time from first mood episode to diagnosis (years) | 10.76 | 8.83 | 12.33 | 9.98 | ||
| BIS scale score | 16.61b | 4.95 | 22.50 | 2.70 | 22.43 | 4.12 |
| BAS-RR scale score | 15.00 | 2.56 | 16.44 | 2.58 | 16.00 | 2.60 |
| BAS-FS scale score | 10.06 | 2.94 | 11.69 | 2.08 | 11.21 | 2.81 |
| BAS-D scale score | 9.00 | 2.81 | 10.62 | 2.75 | 10.57 | 2.65 |
| N | % | N | % | N | % | |
| Family history of bipolar disorderc | 7 | 46 | 5 | 36 | ||
| Female | 13 | 65 | 11 | 64 | 9 | 60 |
| Taking mood stabilizersd | 12 | 75 | 10 | 67 | ||
| Taking antipsychoticse | 9 | 56 | 3 | 20 | ||
| Taking antidepressantsf | 6 | 37 | 6 | 40 | ||
| Comorbid anxiety | 5 | 29 | 4 | 27 | ||
aBIS=behavioral inhibition system; BAS=behavioral activation system; RR=reward responsiveness; FS=fun seeking; D=drive.
bSignificant differences between comparison subjects and patient groups (p<0.05). Bipolar I and bipolar II patients did not differ significantly on any measure.
cFamily history of bipolar disorder up to second-degree relatives. This information was missing from two bipolar I patients and one bipolar II patient.
dThere is no dose equivalence available in the literature for mood stabilizers; however, almost all bipolar I and bipolar II patients taking mood stabilizers in our sample were taking lithium, 800 mg/day, or sodium valproate, 1,000 mg/day, with no significant differences in dosage of these medications between the two patient groups.
eBipolar I patients were taking a mean chlorpromazine-equivalent dosage of 428 mg/day, and bipolar II patients were taking a mean chlorpromazine-equivalent dosage of 259 mg/day.
fBipolar I patients were taking a mean imipramine-equivalent dosage of 164 mg/day, and bipolar II patients were taking a chlorpromazine-equivalent dosage of 151 mg/day.