Table 3. Demographic and clinical characteristics of MDD and control samples.

Characteristic	MDD (n = 39)	Control (n = 113)
Female sex, No. (%)	34 (87)	44 (39)
Age, mean (SD), y	36 (11)	27 (7)
Race/ethnicity
Caucasian, No. (%)	27 (69)	77 (68)
African American, No. (%)	7 (18)	20 (18)
Asian, No. (%)	0 (0)	8 (7)
Mixed/other ancestry, No. (%)	5 (14)	8 (7)
17-item Hamilton depression scale, mean (SD)	23 (5)
Atypical features, No. (%) †	7 (18)
Melancholic features, No. (%) †	11 (29)
Co-morbid anxiety disorder, No. (%) †	12 (32)
First-episode (vs recurrent), No. (%) †	11 (29)
Age of onset, mean (SD), y ‡	25 (13)
Duration of episode, mean (SD), mo ‡	21 (25)

^†Data unavailable for 1 subject

^‡Data unavailable for 4 subjects