Contrast sensitivity in seasonal and nonseasonal depression (original) (raw)
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Mesopic Visual Contrast Sensitivity in Patients with Major Depression
Open Journal of Depression, 2013
The present study evaluated the effects of major depression on visual contrast sensitivity (CS) at low mesopic luminance (.7 cd/m 2 mean luminance), a condition that has been little explored in the literature. We measured spatial visual CS in 20 male volunteers aged 20 -30 years, including 10 healthy individuals and 10 medicated individuals with major depression, to linear sine-wave gratings of .25, 1.0, and 4.0 cycles per degree (cpd) of visual angle using the psychophysical staircase method with forced choice. The average spatial visual CS in the depressed group was approximately 1.7 lower than the average spatial visual CS in the control group. However, the post hoc test showed significant differences only at the spatial frequencies of .25 and 1.0 cpd (p < .05), which are likely processed by the magnocellular visual pathway. These results suggest that spatial visual CS to sine-wave gratings should be used to evaluate the responsiveness of the visual system in patients with major depression under conditions of low luminance.
World Journal of Biological Psychiatry, 2009
Background. Reduced dopaminergic transmission has been implicated in the pathophysiology of major depression. Furthermore, dopaminergic neurotransmission plays an important role in the physiology of visual contrast sensitivity (CS). To test the hypothesis that altered dopaminergic neurotransmission plays a role in major depression we measured contrast sensitivity in patients with major depression and in healthy control subjects. Methods. Twenty-eight patients diagnosed with major depressive disorder were compared to 21 age-matched control subjects on their ability to detect a Gabor target with slightly elevated luminance contrast embedded in seven equi-contrast distracters. Results. Contrast discrimination thresholds were significantly elevated in unmedicated and medicated patients with major depression compared to control subjects, at all pedestal contrast levels tested. Conclusions. Contrast discrimination performance is reduced in depressive patients and might reflect a state of altered dopaminergic neurotransmission.
Light therapy increases visual contrast sensitivity in seasonal affective disorder
Psychiatry Research, 2004
The purpose of this study was to investigate the effects of light therapy on visual contrast sensitivity in patients with seasonal affective disorder (ns10) and healthy control subjects (ns10). Static and dynamic visual contrast sensitivity was measured using a Venus system before and after 4 weeks of light therapy (10 000 lux, 30 min, 5 times a week). Light therapy increased static visual contrast sensitivity in the patients. We found no significant difference between the patients and controls either before or after light therapy. These results raise the possibility that light therapy induces retinal sensitization in seasonal affective disorder. ᮊ
Retinal pigment epithelium response and the use of the EOG and arden ratio in depression
Psychiatry Research, 1991
Supersensitivity to light in depression has been observed with both neuroendocrine and ophthalmological assessment methods. The biological defect underlying this abnormality may be localized in either the photoreceptors, the retinal pigmented epithelium, or some interaction of the two. The present study assessed responses of the retinal pigmented epithelium (RPE). All subjects underwent thorough ophthalmological and mood assessments. The electrooculogram (EOG) was used to measure standing potentials of the RPE in response to light and dark in 20 normal controls and 20 unmedicated depressed patients. Both groups were matched for age, sex, time of day for the procedure, and prior lighting history. Reproducibility of the EOG measure on two independent occasions for 13 control subjects had an intrasubject reliability coefficient of 0.70. The mean f SD Arden Ratio (light peak/dark trough) of the control group (2.13 f 0.42) compared to the depressed group (2.28 f 0.72) showed no statistical difference. There was, however, a significant difference between groups in response to darkness; depressed patients had a lower standing potential in the dark compared to controls, suggesting supersensitivity to light. No difference between groups was detected in standing potentials at baseline or in response to light. Supersensitivity to light in depression may be related to abnormal function of the RPE, but the inherent reliability of the EOG precludes the use of this instrument in pursuing this hypothesis.
Diminished perception of ambient light: a symptom of clinical depression?
Journal of Affective Disorders, 2000
Objective: In a non-randomized, uncontrolled pilot study, the authors investigated whether depressed patients were more likely to perceive the lighting in their environment as being dimmer than usual. Method: 120 patients (46 males, 74 females) who presented for possible admission for depression at a psychiatric facility were administered a Diagnostic and Statistical Manual of disorders (DSM-IV) based questionnaire and underwent psychiatric evaluation. A question asking whether 'the lights in my surroundings seem dimmer than usual' was included in the 15-point question survey. Statistical analyses were performed to determine whether an affirmative response to this dimness question was correlated with the depth of depression (mild, moderate, severe) and also whether significant correlation was present between the percentage of patients answering yes to the dimness question versus the number of yes responses to the core symptoms of depression. Results: Two thirds of the patients categorized as severely depressed responded that their ambient environment appeared dimmer than usual compared to 21% of moderately and 14% of mildly depressed patients. This difference was statistically significant (P , 0.05). The degree of depression as determined by the number of core questions answered affirmatively and the presence of this 'dimness' symptom were highly correlated (P 5 0.002, R 5 0.87). Limitations: The specificity of the finding has not been tested in reference to non-affective psychiatric patient groups. Conclusion: A patient's perception of the ambient light in the environment being dimmer than usual may be an important symptom of a major depressive disorder. Further replication and objective testing of visual function in depressed patients appears warranted.
Pupillary response abnormalities in depressive disorders
Psychiatry Research, 2016
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. Melanopsinmediated 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.
2011
Using functional magnetic resonance imaging (fMRI), we recently demonstrated that nonmedicated patients with a first episode of unipolar major depression (MDD) compared to matched controls exhibited an abnormal neural filtering of irrelevant visual information (Desseilles et al., 2009). During scanning, subjects performed a visual attention task imposing two different levels of attentional load at fixation (low or high), while task-irrelevant colored stimuli were presented in the periphery.
Adaptation to dim light in depressed patients with seasonal affective disorder
Psychiatry Research, 1991
Supersensitivity to light has been suggested as a possible trait marker for manic-depressive illness. Because winter seasonal affective disorder (SAD) is associated with depressive episodes during dark winter days, the authors postulated that SAD patients would show diminished sensitivity to dim light. Darkadaptation curves were obtained in IO medication-free, depressed SAD patients and in 10 age-and sex-matched drug-free healthy controls. Contrary to the hypothesis, patients adapted to dim light more rapidly than controls.
Biological Cybernetics, 1979
The hypothesis that neural processing in the human visual pathways compensates for both optical degradation as well as noise contamination at the photoreceptor level is introduced and shown to be consistent with the high frequency portion of the contrast sensitivity function for threshold detection of sinusoidal gratings in addition to the suprathreshold phenomenon of matching sinusoidal gratings of different spatial frequencies. This offers a unifying interpretation for why, at threshold conditions, the high spatial frequency portion of the image is blurred as severely by the nervous system as it is by the optics (e.g. Campbell and Green, 1965) while in extreme suprathreshold conditions the nervous system effectively deblurs the image (e.g. Georgeson and Sullivan, 1975; Kulikowski, 1976). These conclusions do not necessitate a highly specific form of visual processing such as Fourier channeling.