Pupillary response abnormalities in depressive disorders.
Depressive disorders lack objective physiological measurements to characterize the affected population and facilitate study of relevant mechanisms. The melanopsin-mediated light signaling pathway may contribute to seasonal variation and can be measured non-invasively by pupillometry. We prospectively studied changes in melanopsin-mediated pupillary constriction in 19 participants with major depressive disorder (MDD) and 10 control across the summer and winter solstices. The melanopsin-mediated response, as measured by the pupil's sustained constriction six s after a high intensity blue light stimulus, was marginally attenuated in those with MDD relative to controls (p=0.071). The participants with MDD unexpectedly showed a significantly reduced transient pupillary response to low intensity red (p=0.011) and blue light (p=0.013), but not high intensity red and blue light. Sustained pupillary constriction in response to high intensity blue light was more pronounced with increasing daylight hours (p=0.037) and was more strongly related to objectively measured versus estimated light exposure. Melanopsin-mediated impairments in pupil response may serve as a biological marker for vulnerability to depression in low light conditions. Assessment of these and other responses to light stimuli, such as response to low intensity light, may be useful for the study of the neurobiology of MDD and related mood disorders.
Department of Psychiatry, Roy J. and Lucille A. Carver College of Medicine, United States.
Scott A
SA
Laurenzo
Department of Ophthalmology, Roy J. and Lucille A. Carver College of Medicine, United States; Iowa City Veterans Affairs center for Prevention of Visual Loss, Department of Veterans Affairs Hospital, United States.
Randy
R
Kardon
Iowa City Veterans Affairs center for Prevention of Visual Loss, Department of Veterans Affairs Hospital, United States; Tippie College of Business, The University of Iowa, Iowa City, IA 52242, USA.
Johannes
J
Ledolter
Department of Ophthalmology, Roy J. and Lucille A. Carver College of Medicine, United States; Iowa City Veterans Affairs center for Prevention of Visual Loss, Department of Veterans Affairs Hospital, United States.
Pieter
P
Poolman
Department of Psychiatry, Roy J. and Lucille A. Carver College of Medicine, United States.
Ashley M
AM
Schumacher
Department of Psychiatry, Roy J. and Lucille A. Carver College of Medicine, United States.
James B
JB
Potash
Department of Ophthalmology, Roy J. and Lucille A. Carver College of Medicine, United States; Iowa City Veterans Affairs center for Prevention of Visual Loss, Department of Veterans Affairs Hospital, United States.
Jan M
JM
Full
Department of Ophthalmology, Roy J. and Lucille A. Carver College of Medicine, United States; Iowa City Veterans Affairs center for Prevention of Visual Loss, Department of Veterans Affairs Hospital, United States.
Olivia
O
Rice
Department of Ophthalmology, Roy J. and Lucille A. Carver College of Medicine, United States; Iowa City Veterans Affairs center for Prevention of Visual Loss, Department of Veterans Affairs Hospital, United States.
Anna
A
Ketcham
Department of Ophthalmology, Roy J. and Lucille A. Carver College of Medicine, United States; Iowa City Veterans Affairs center for Prevention of Visual Loss, Department of Veterans Affairs Hospital, United States.
Cole
C
Starkey
Department of Psychiatry, Roy J. and Lucille A. Carver College of Medicine, United States; Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, United States; Department of Epidemiology, College of Public Health, United States.
Jess G
JG
Fiedorowicz
D000293:Adolescent; D000328:Adult; D003865:Major Depressive Disorder / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008027:Light; D008297:Male; D008875:Middle Aged; D011680:Pupil / Q000502:physiology*; D012025:Reflex, Pupillary / Q000502:physiology*; D055815:Young Adult
Bipolar disorder; Major depressive disorder; Pupillometry; Seasonality