Neurological

Depression can alter the cortical processing of visual contrast

According to a study published in the Journal of Psychiatry and Neuroscience, major depressive episodes are associated with altered cortical processing of visual contrast in some patients.

Between 2013 and 2016, the investigators recruited people for a healthy control group (n = 29) as well as patients (n = 111) in Finland using the adaptive staircase method and a 2-alternative forced choice task. After 7 months, 74 patients were re-examined.

The patient cohort included people with unipolar major depression (MDD; n = 46), bipolar disorder (BD; n = 38), and borderline personality disorder (BPD; n = 27). The MDD, BD, BPD, and people in the control groups included 58.7%, 71.1%, 74.1%, and 72.4% women, and had mean ages of 31.8 ± 10.1, 32.0 ± 9 , 3, 28.0 ± 7.3 and 32.1 ± 9.0 years. respectively.

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During the brightness induction test, no significant differences between patients and individuals in the control group were observed (t[39.8], 0.534; d, 0.115; P = .60). The investigators found significant group differences for the contrast medium suppression test (t[35.2], 2.902; d, 0.663; P = 0.006), in which the patients showed significant orthogonal differences (t[131], 2.80; P = .006) but no collinear differences (t[131], 1.55; P = .12).

These observations showed that the patients had reduced contrast suppression, the illusion was less strong and stimuli were perceived more truthfully than in the participants in the control group.

Group differences could not be explained by a model that included age, gender, patient subgroups, medication use, extroversion, conscientiousness, neuroticism, tolerability, openness or alcohol consumption (F.[11,80], 1.105; R2, 0.132; P = .37).

By using mood stabilizers (F.) The brightness induction was slightly increased and the contrast suppression decreased[1,104], 6.024; 2, 0.053; P = 0.016). However, the pairwise comparison was not significant (contrast suppression: t[17.26], -2,095; P = 0.051; Brightness induction: t[16.46], 1.269; P = .22).

At 7-month follow-up, 56.4% of the MDD, 60.6% of the BD and 52.2% of the BPD cohorts were in remission from their depressive episode. In the reassessment, the depressive values ​​did not correlate significantly with the brightness induction (r[67], 0.073; P = .556) or contrast suppression (r[73], -0.156; P = .189).

This study was limited by the potential impact of behavior on eye test results and the fact that retinal and cortical processing were indirectly derived.

reference

Salmela V, Socada L, Söderholm J, et al. Reduced visual contrast suppression during depressive episodes. J Psychiatry Neurosci. 2021; 46 (2): E222-E231. doi: 10.1503 / jpn.200091

This article originally appeared on Ophthalmology Advisor

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