Table 1.

Sample demographics

Demographic variable	Subjects with bipolar disorder (N=34)		Healthy Subjects (N=31)		Group difference
	Mean	SD	Mean	SD
Age (years)	38.1	12.0	37.8	13.1	t=−0.110, p=0.91
Education levela	3.0	0.6	3.2	0.6	p=0.36
HAMDb	4.5	2.3	-	-	-
YMRSc	1.7	2.2	-	-	-
Duration of illness (years)	19.8	12.5	-	-	-
Age at onset	18.2	7.5	-	-	-
Prior manias	7.7	11.6	-	-	-
Prior depressions	8.4	11.0	-	-	-
Prior hospitalizations	2.6	2.7	-	-	-
Prior hospitalizations for mania	1.7	1.7	-	-	-
Prior hospitalizations for depression	0.9	1.3	-	-	-
Duration between diagnosis and first medication treatment (years)	8.5	9.9	-	-	-
	N	%	N	%
Female	13	38	13	42	p=1.00
Race
Caucasian	25	73	21	67	p=0.18
Asian	2	6	7	23	-
African American	6	18	3	10	-
Other	1	3	0	0	-
History of psychosis	17	50	-	-	-
Patient medications
Unmedicated	10	29	-	-	-
Lithium	0	0	-	-	-
Anticonvulsantsd	18	53	-	-	-
Antipsychoticse	17	50	-	-	-
Antidepressantsf	9	26	-	-	-
Benzodiazapineg	1	3	-	-	-

^aEducational level for each subject was rated on a four-point scale (1, grade 8 or less; 2, grade 9–12; 3, 1–4 years of college or university; 4, four or more years of college or university);

^bHamilton Depression Rating Scale;

^cYoung Mania Rating Scale;

^dincludes treatment with Divalproex sodium (N=5), Lamotrigine (N=10), Oxcarbazepine (N=1) or Carbamazepine (N=2);

^eincludes treatment with Aripiprazole (N=8), Risperidone (N=1), Ziprasidone (N=1), Olanzapine (N=3), Quetiapine (N=4);

^fincludes treatment with Paroxetine (N=1), Fluoxetine (N=2), Citalopram (N=1), Escitalopram (N=1), Venlafaxine (N=1), Bupropion (N=2), Trazodone (N=1);

^gincludes treatment with Temazepam (N=1). Months euthymic indicated time euthymic prior to scanning. All p values indicate 2-tailed significance levels.