Sociodemographic characteristics of the study population (n = 105)*
| Characteristic | Control (n = 60) | Bipolar disorder type I (n = 45) | Test statistic | p value |
|---|---|---|---|---|
| Age, yr | 30.7 ± 8.3 | 31.9 ± 8.1 | t = 0.73 | 0.47 |
| Female, n (%) | 32 (53.3) | 25 (55.6) | χ2 = 0.82 | 0.84 |
| Body mass index, kg/m2 | 25.6 ± 5.2 | 26.6 ± 4.4 | t = 1.00 | 0.32 |
| Education, yr | 15.9 ± 2.8 | 15.9 ± 3.3† | t = 0.09 | 0.92 |
| Smoking status, n (%) | χ2 = 5.37 | 0.07 | ||
| Yes | 16 (26.7) | 13 (28.9) | ||
| No | 42 (70.0) | 25 (55.6) | ||
| Past | 2 (3.3) | 7 (15.6) |