Elsevier

Psychiatry Research

Volume 118, Issue 3, 15 June 2003, Pages 259-271
Psychiatry Research

Pattern-reversed visual evoked potentials in subtypes of major depression

https://doi.org/10.1016/S0165-1781(03)00097-0Get rights and content

Abstract

There are no articles in the international psychiatric literature reporting subclinical visual system disorders in depressed patients, although a disturbance of circadian rhythms is one of the prominent theories of the etiopathogenesis of depression. Fifty patients aged 21–60 years suffering from major depression according to DSM-IV criteria, and 20 controls took part in the study. Diagnosis was obtained with the aid of the Schedules for Clinical Assessment in Neuropsychiatry version 2.0. Psychometric assessment included the Hamilton Depression Rating Scale, the Hamilton Anxiety Scale, the 1965 and 1971 Newcastle Scales, and the Diagnostic Melancholia Scale. All subjects had normal electroretinographic and flash-visual evoked potential (VEP) recordings. Pattern-reversed VEPs (PR-VEPs) were recorded from each eye separately. Three-way analysis of covariance, Student's t-test and Pearson product–moment correlation coefficients were used for the analysis. All recordings were within the normal range. N80 and P100 latency were significantly shorter in atypical and significantly longer in melancholic patients. There was a positive correlation between N80 and P100 latency and age of onset and melancholic indices, and a negative correlation with the presence and the number of life events precipitating onset. The results of the current study suggest that PR-VEPs are consistent with other biological data supporting the atypical-melancholic distinction. The most important finding was the strong negative relationship between PR-VEP latency and stressful life events. The current study also provided data inconsistent with the hyperarousal theory and in support of an arousal dysregulation hypothesis for major depression.

Introduction

Modern classification systems recognize melancholic (‘somatic’) and atypical features (Fountoulakis et al., 1999b). In spite of early reports (Dally and Rohde, 1961, Liebowitz et al., 1988, Sargant, 1960, West and Dally, 1959) concerning the ‘atypical syndrome’ (with reverse neurovegetative symptoms), today the only finding that continues to be robust is not the favorable response of atypical patients to monoamine oxidase inhibitors, but their resistance to tricyclic antidepressants. Atypical depression is considered to constitute a risk factor for further mental suffering (Tsolaki et al., 1997, Fountoulakis et al., 2000). It is suggested that the subtype of depression is also of prime importance in event-related potential (ERP) studies (Shagass, 1981).

Electrophysiological methods, although spatially removed from the events they record, are possibly closer in time to these events in comparison to cerebrospinal fluid, urine and peripheral blood testing. Relationships between electrophysiological testing and peripheral biological markers have been reported in depression (Buchsbaum et al., 1971a, Buchsbaum et al., 1973a, Buchsbaum and Wender, 1973b). Studies on primates also support the usefulness of these methods and the relationship of catecholaminergic activity with visual information processing (Redmond et al., 1975), possibly reflecting a secondary elaboration or process enabling the organism to choose the appropriate motoric or affective response (Bruder et al., 1992). However, although some features of the ERP (e.g. the amplitude and latency response to varying levels of stimulus intensity; Buchsbaum, 1974) might be heritable, ERPs are generally considered to reflect state-related rather than trait-related processes (Shagass, 1979).

Articles on the visual system of depressives (Buchsbaum et al., 1971a, Buchsbaum et al., 1977, Fotiou et al., 1999, Fountoulakis et al., 1999a) and Alzheimer's disease patients (Fotiou et al., 2000) have shown that the assessment of the visual system may provide valuable information about different diseases affecting the central nervous system (CNS).

The hypothesis under investigation in the current study was that melancholic patients may manifest reduced conduction velocity in the brain, and this could be related to differences in their response to life events as suggested by several authors (Buchsbaum et al., 1973a, Buchsbaum, 1975, Fotiou et al., 1999). Another hypothesis under investigation in the current study was whether there is a difference in the conduction velocity between hemispheres, since this could lead to a disruption in the flow and processing of information in the brain and thus could lead to affective disorders.

The rationale behind the use of pattern-reversed visual evoked potentials (PR-VEPs) was that they constitute a marker for the conduction velocity in the CNS, are highly reliable (compared with flash-VEPs), are short-latency potentials (below 200 ms), and thus demand minimum effort and collaboration from the subject (in contrast to long-latency potentials).

Since severity is frequently confounded with specific clinical features (e.g. suicidality and psychomotor changes), and different scales and criteria sets reflect different approaches to this problem, the simultaneous use of multiple rating scales was judged to be necessary.

Section snippets

Subjects

Fifty (15 males and 35 females) patients suffering from major depression according to DSM-IV (American Psychiatric Association, 1994) and depression according to ICD-10 criteria (World Health Organization, 1993) took part in the study. The patients ranged in age from 21 to 60 years (mean=41.0, S.D.=11.4). The patients were compared with a control group (n=20 controls, 7 males and 13 females, aged 20–55 years, mean=36.7, S.D.=8.9). All subjects provided written informed consent. Fourteen of the

Results

Depressed patients and controls had similar gender composition and did not differ significantly in age (P=0.107). Patients of the melancholic subtype tended to be older than the other subjects, but not significantly so (Table 1). However, age was entered in the analysis as a covariate to rule out the possibility that it might constitute a confounder. There were twice as many women as men in the sample (70% vs. 30%), which is a common problem in studies of depression (Zimmerman et al., 1985).

A

Discussion

Melancholic patients might have reduced transmission velocity in the CNS, as is suggested by prolonged latency of the b-wave of the electroretinogram (Fotiou et al., 1999). The present study provides further data to support this. The main finding was that melancholic patients had prolonged, while atypical patients had shorter PR-VEP latencies especially from the dominant right eye (Fig. 1). This, together with the normal values of the ratio O1/O2 latencies, in all depressed subtypes (Table 2),

Acknowledgements

The authors wish to thank the Editor and three anonymous reviewers for their assistance in the interpretation of the results and the final formation of the manuscript.

References (59)

  • K.A. Keefe et al.

    Environmental stress increases extracellular dopamine in striatum of 6-hydroxydopamine-treated rats: in vivo microdialysis studies

    Brain Research

    (1990)
  • M. Papp et al.

    Pharmacological validation of the chronic mild stress model of depression

    European Journal of Pharmacology

    (1996)
  • E. Przegalinski et al.

    The effect of 5-HT1A receptor ligands in a chronic mild stress model of depression

    Neuropsychopharmacology

    (1995)
  • D.E. Redmond et al.

    Evoked potential studies of brain catecholamine alterations in monkeys

    Journal of Psychiatric Research

    (1975)
  • W. Sargant

    Some newer drugs in the treatment of depression and their relation to other somatic treatments

    Psychosomatics

    (1960)
  • C. Shagass

    Neurophysiological evidence for different types of depression

    Journal of Behavioral Therapy and Experimental Psychiatry

    (1981)
  • C. Shagass et al.

    Evoked potential topography in major depression I: Comparisons with non-patients and schizophrenics

    International Journal of Psychophysiology

    (1992)
  • C. Shagass et al.

    Evoked potential topography in major depression II: Comparison between subgroups

    International Journal of Psychophysiology

    (1992)
  • A. Tazi et al.

    Schedule-induced polydipsia experience decreases locomotor response to amphetamine

    Brain Research

    (1988)
  • A. Tazi et al.

    Pituitary-adrenal correlates of schedule-induced polidipsia and wheel running in rats

    Behavioral Brain Research

    (1986)
  • H Akiskal et al.

    Overview of recent research in depression: intergration of 10 conceptual models into a comprehensive clinical frame

    Archives of General Psychiatry

    (1975)
  • American Psychiatric Association, 1994. DSM-IV. Diagnostic and Statistical Manual of Mental Disorders, 4th Edn. Author,...
  • P. Bech

    Rating scales for psychopathology

  • J.L. Bradshaw

    Asymmetries in non-living and living systems

  • G.E. Bruder

    P300 findings for depressive and anxiety disorders

    Annals of the New York Academy of Sciences

    (1992)
  • G.E. Bruder et al.

    Cerebral laterality and depression: differences in perceptual asymmetry among diagnostic subtypes

    Journal of Abnormal Psychology

    (1989)
  • G.E. Bruder et al.

    Cerebral laterality and depression: relations of perceptual asymmetry to outcome of treatment with TCAs

    Neuropsychopharmacology

    (1990)
  • G.E. Bruder et al.

    Brain ERPs of depressed patients to complex tones in an oddball task: relation of reduced P3 asymmetry to physical anhedonia

    Psychophysiology

    (1998)
  • M. Buchsbaum

    Average evoked response augmenting/reducing in schizophrenia and affective disorders

  • Cited by (0)

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