Is there a dysfunction in the visual system of depressed patients ? Konstantinos

Background: The aim of the current study was to identify a possible locus of dysfunction in the visual system of depressed patients. Materials and Methods: Fifty Major Depressive patients aged 21–60 years and 15 age-matched controls took part in the study The diagnosis was obtained with the SCAN v 2.0. The psychometric assessment included the HDRS, the HAS, the Newcastle Scales, the Diagnostic Melancholia Scale and the GAF scale. Flash Electroretinogram and Electrooculogram were performed in all subjects. The statistical analysis included ANCOVA, Student's t-test and Pearson Product Moment Correlation Coefficient were used. Results: The Electro-oculographic findings suggested that all subtypes of depressed patients had lower dark trough and light peak values in comparison to controls (p < 0.001), while Arden ratios were within normal range. Electroretinographic recordings did not reveal any differences between patients and controls or between subtypes of depression. Discussion: The findings of the current study provide empirical data in order to assist in the understanding of the international literature and to explain the mechanism of action of therapies like sleep deprivation and light therapy. Background Depression, according to recent epidemiological surveys might affect almost 25% of the general population at some point of their lives. The definition of 'depression' according to both classification systems [1-3], is based on the definition of the depressive episode. Modern classification systems recognise melancholic ('somatic) and atypical features. In spite of early reports [4-7], today the only report which seems to survive is not the favourable response of atypical patients to MAOIs, but their resistance to TCAs. One of the theories concerning the etiopathogenesis of depression suggests that a disturbance of biological rhythms is the core feature [8]. This disturbance is better studied in Seasonal Affective Disorder (SAD), which is a Published: 29 March 2005 Annals of General Psychiatry 2005, 4:7 doi:10.1186/1744-859X-4-7 Received: 27 January 2005 Accepted: 29 March 2005 This article is available from: http://www.annals-general-psychiatry.com/content/4/1/7 © 2005 Fountoulakis et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.