Spontaneous eye blink rate in winter seasonal affective disorder.
We investigated spontaneous eye-blink rates in 19 drug-free patients with winter seasonal affective disorder (SAD) and 18 normal control subjects. At baseline, there were no significant differences between the two groups (mean +/- SD blink rate: 15/minute +/- 8 vs. 15/minute +/- 7). Light therapy (10,000 lux: 1 hour each morning for 1 week) produced no significant change in mean (+/- SD) blink rates either in 10 SAD patients (13/minute +/- 8 vs. 10/minute +/- 7) or in 12 normal control subjects (15/minute +/- 6 vs. 14/minute +/- 6). A post hoc exploratory analysis of the effect of light therapy on premenopausal female subjects (5 patients and 9 control subjects) showed a significant decrease in mean (+/- SD) blink rate in the patients after treatment (17 +/- 6 vs. 12 +/- 8 compared with 15 +/- 7 vs. 16 +/- 5). These results do not support the idea that an elevated blink rate may be a general biological marker in SAD, but they suggest a possible link between light treatment and mechanisms that regulate blink rate in premenopausal SAD patients.
Barbato
G
G
Section on Environmental Psychiatry, National Institute of Mental Health, Bethesda, MD 20892.
Moul
D E
DE
Schwartz
P
P
Rosenthal
N E
NE
Oren
D A
DA
D000328:Adult; D001767:Blinking / Q000502:physiology* / Q000528:radiation effects; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010555:Personality Inventory; D010789:Phototherapy; D011930:Reaction Time / Q000502:physiology* / Q000528:radiation effects; D011954:Receptors, Dopamine / Q000502:physiology; D016574:Seasonal Affective Disorder / Q000503:physiopathology* / Q000628:therapy; D012621:Seasons
D011954:Receptors, Dopamine