Table 3. Clinical features and lifetime comorbidity in youths having bipolar disorder with and without externalizing disorders

Externalizing

No externalizing

   

n = 12

n = 31

c2

p

Age, mean (SD)

12.6 (4.5)

15.8 (1.7)

–3.42

0.001

Age at onset, mean (SD)

9. 5 (3.48)

13.35 (1.85)

–4.72

0.0001

Clinical global impression, mean (SD)

4.67 (0.65)

4.93 (0.83)

–1.0

ns

Bipolar disorder

       

Type I, n (%)

2 (16.7)

22 (71.0)

 

Type II, n (%)

10 (83.3)

9 (29.0)

10.34

0.001

Lifetime comorbidity, n (%)

       

Obsessive–compulsive disorder

4 (33.3)

15 (48.4)

0.79

ns

Social phobia

4 (33.3)

13 (41.9)

0.27

ns

Panic disorder or agoraphobia

2 (16.7)

9 (29.0)

0.69

ns

Separation anxiety disorder

2 (16.7)

5 (16.1)

0.002

ns

Generalized anxiety disorder

2 (16.7)

6 (19.3)

0.041

ns

Comorbid anxiety disorders, mean (SD)

1. 17 (1.19)

1.51 (1.18)

–0.87

ns

Pharmacologic hypomania, n (%)

3 (25.0)

9 (29.0)

0.07

ns

Index episode, n (%)

       

Depressive

7 (58.3)

11 (35.5)

 

(Hypo)mania

1 (8.3)

13 (41.9)

 

Mixed

4 (33.3)

7 (22.6)

4.47

ns