Table 1.
Sample Demographics
| Lithium-Positive Patients with Bipolar Disorder (n = 20) |
Lithium-Negative Patients with Bipolar Disorder (n = 8) |
Healthy Comparison Subjects (n = 28) |
Between-Group Differences |
|
|---|---|---|---|---|
| Age (Mean ± SD) | 35.1 ± 10.8 | 38.6 ± 10.0 | 35.9 ± 8.5 | F = .40, p = .67 |
| % Female (n) | 45% (9) | 4 (50%) | 39% (11) | χ2 = .35, p = .84 |
| % Right Handed (n) | 100% (20) | 100% (8) | 100% (28) | χ2 = .00, p = 1.0 |
| Education Level | 15.0 ± 2.7 | 15.5 ± 3.3 | 15.4 ± 2.7 | F = .20, p = .82 |
| Race | ||||
| % Caucasian (n) | 100% (20) | 88% (7) | 89% (25) | χ2 = 4.1, p = .25 |
| % Asian (n) | 0 | 0 | 4% (1) | |
| % African American (n) | 0 | 0 | 7% (2) | |
| % Biracial (n) | 0 | 4% (1) | 0 | |
| % Bipolar I Disorder | 90% (18) | 50% (4) | χ2 = 5.43, p = .04 | |
| % Bipolar II Disorder | 10% (2) | 50% (4) | NA | |
| HDRS | 6.9 ± 8.6 | 15.3 ± 11.8 | NA | F = 3.76, p = .07 |
| Bech-Rafaelsen Mania Scale | .67 ± 1.7 | 1.63 ± 2.0 | NA | F = 1.31, p = .27 |
| Duration of Illness (Years) | 15.1 ± 8.2 | 15.1 ± 8.3 | NA | F = .00, p = .99 |
| Age at Onset | 18.6 ± 6.1 | 23.5 ± 7.8 | NA | F = 3.03, p = .094 |
| Number of Episodes | 20.5 ± 25.9 | 16.3 ± 17.5 | NA | F = .16, p = .70 |
| Current Mood State | χ2 = 4.13, p = .13 | |||
| Depressed | 30% (6) | 50% (4) | NA | |
| Hypomanic | 0% (0) | 12% (1) | ||
| Euthymic | 70% (14) | 38% (3) | ||
| % with Previous (Lifetime) | ||||
| Antipsychotic Use (n) | 25% (5) | 12% (1) | NA | χ2 = .89, p = .64 |
Mean ± standard deviation, age, and education levels are expressed in years.
HDRS, Hamilton Depression Rating Scale.