Table 2.
Primary BD | Secondary BD | Statistics | |
---|---|---|---|
N = 117 | N = 34 | ||
Age, y, mean (SD) | 36.50 (12.2) | 33.7 (10.4) | t = 1.2, df = 149, P = 0.227a |
AAO, y, mean (SD) | 21.8 (9.0) | 25.9 (9.8) | t = −2.3, df = 149, P = 0.020 a |
Age at onset of excessive substance use, y, mean (SD)* | 27.0 (11.6) | 20.1 (7.0) | t = 2.9, df = 64, P = 0.005 a |
Gender, female, n (%) | 74 (63.2) | 18 (52.9) | χ² = 1.2, df = 1, P = 0.278b |
Type I BD, (%) | 68 (58.1) | 23 (67.6) | χ² = 1.0, df = 1, P = 0.318b |
Family history of affective/psychotic disorder, n(%) | 45 (39) | 17 (52) | χ² = 1.6, df = 1, P = 0.204b |
Significant P-values are typed in bold
BD Bipolar disorder, AAO Age at onset of BD, y Years
* For the 32 patients with excessive substance use in the primary BD group
aStudent’s t-test
bChi-square test