Co-administration of atypical antipsychotics and antidepressants disturbs contrast detection in schizophrenia

Sheremata, Summer; Chen, Y

doi:10.1016/j.schres.2003.09.005

Cited by 8 publications

(5 citation statements)

References 20 publications

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“…Further complicating the synthesis of CS findings in schizophrenia is that various methodologies have been used to measure CS. For instance, studies with unmedicated first-episode patients or those at high-risk used a "steady-pedestal" task (Kelemen et al, 2013;Keri & Benedek, 2007;Kiss et al, 2010), whereas studies with more chronic patients, such as those tested in our laboratory, have used a spatial forced-choice method (Butler et al, , 2009, and others have used a temporal forced-choice method that involves a memory load (Chen et al, 2003;Sheremata & Chen, 2004). Furthermore, some studies have only investigated CS at a single spatial frequency (Cadenhead et al, 2013;Chen et al, 2003), while others have investigated CS at various spatial frequencies (Butler et al, , 2009Keri et al, 2002;Slaghuis, 1998Slaghuis, , 2004.…”

Section: Factors Affecting Contrast Sensitivity In Schizophreniamentioning

confidence: 99%

Contrast sensitivity deficits in schizophrenia: A psychophysical investigation

Zemon

Herrera

Gordon

et al. 2020

Eur J of Neuroscience

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Individuals with schizophrenia have problems with visual contrast processing. The current study investigated contrast sensitivity (CS) in schizophrenia/schizoaffective disorder to elucidate the underlying neural mechanisms affected by this disorder and to identify critical testing conditions that distinguish individuals with the disorder from healthy individuals. Principal component analysis was applied to the data (N = 143) to separate responses from distinct visual pathways. Participants were 68 patients and 75 age-similar controls. CS was obtained using a forced-choice psychophysical paradigm with grating patterns of low to high spatial frequency presented at short and long durations. Linear mixed-effects models were used to examine differences in log CS with respect to group, duration, and stimulus condition. Lower CSs were found in patients compared to controls over all stimulus conditions with the magnitude of deficits dependent on both spatial frequency and stimulus duration. Log CSs to low and high spatial frequencies loaded onto separate principal components, supporting the existence of two psychophysical mechanisms, transient and sustained. Critical conditions were identified to tap each mechanism. Visual acuity was correlated moderately with log CS to high, but not low, spatial frequencies, and deficits found for acuity and CS to moderate/high spatial frequencies (4-21 cycles/ degree) appear to reflect dysfunction in the sustained mechanism. CS deficits found at the lowest spatial frequency tested (0.5 cycles/degree) appear to reflect dysfunction in the transient mechanism. Both types of CS deficits may have diagnostic value and implications for social and neurocognitive deficits in this disorder.

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Section: Factors Affecting Contrast Sensitivity In Schizophreniamentioning

confidence: 99%

Contrast sensitivity deficits in schizophrenia: A psychophysical investigation

Zemon

Herrera

Gordon

et al. 2020

Eur J of Neuroscience

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“…Some studies of schizophrenia patients, however, have found that administration of antipsychotic medications decreases contrast sensitivity for medium and high spatial frequencies ( Harris et al, 1990 , Keri et al, 2002 ), and increases it at low spatial frequencies ( Harris et al, 1990 ). Further evidence suggests that the combination of antipsychotic and antidepressant medication [a combination frequently prescribed due to high rates of depression in schizophrenia ( Siris, 2000 )] is especially detrimental to contrast sensitivity ( Sheremata and Chen, 2004 ). It should be noted here that antipsychotic medications can interfere with vision in ways other than by reducing retinal DA, as instances of toxic maculopathy ( Lee and Fern, 2004 ) and increased risk for cataract ( McCarty et al, 1999 ) have been reported.…”

Section: Dopamine and Retinal Functionmentioning

confidence: 99%

Schizophrenia and the eye

Silverstein

Rosen

2015

Schizophrenia Research: Cognition

159

137

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Although visual processing impairments are common in schizophrenia, it is not clear to what extent these originate in the eye vs. the brain. This review highlights potential contributions, from the retina and other structures of the eye, tovisual processing impairments in schizophrenia and high-risk states. A second goal is to evaluate the status of retinal abnormalities as biomarkers for schizophrenia. The review was motivated by known retinal changes in other disorders (e.g., Parkinson's disease, multiple sclerosis), and their relationships to perceptual and cognitive impairments, and disease progression therein. The evidence reviewed suggests two major conclusions. One is that there are multiple structural and functional disturbances of the eye in schizophrenia, all of which could be factors in the visual disturbances of patients. These include retinal venule widening, retinal nerve fiber layer thinning, dopaminergic abnormalities, abnormal ouput of retinal cells as measured by electroretinography (ERG), maculopathies and retinopathies, cataracts, poor acuity, and strabismus. Some of these are likely to be illness-related, whereas others may be due to medication or comorbid conditions. The second conclusion is that certain retinal findings can serve as biomarkers of neural pathology, and disease progression, in schizophrenia. The strongest evidence for this to date involves findings of widened retinal venules, thinning of the retinal nerve fiber layer, and abnormal ERG amplitudes. These data suggest that a greater understanding of the contribution of retinal and other ocular pathology to the visual and cognitive disturbances of schizophrenia is warranted, and that retinal changes have untapped clinical utility.

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“…Even in the absence of any manipulation, patients need a higher stimulus contrast than controls to detect the presence of a stimulus. Some of these results have been questioned, especially concerning the effects of medication ( Keri et al, 2002 ; Sheremata and Chen, 2004 ), methodology ( Skottun and Skoyles, 2007 ) or the causal role of alterations at the retinal level ( Silverstein and Rosen, 2015 ). More details on paradigms used to explore sensory processing can be found in Table 1 .…”

Section: Introductionmentioning

confidence: 99%

Is Schizophrenia a Disorder of Consciousness? Experimental and Phenomenological Support for Anomalous Unconscious Processing

Giersch

Mishara

2017

Front. Psychol.

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Decades ago, several authors have proposed that disorders in automatic processing lead to intrusive symptoms or abnormal contents in the consciousness of people with schizophrenia. However, since then, studies have mainly highlighted difficulties in patients’ conscious experiencing and processing but rarely explored how unconscious and conscious mechanisms may interact in producing this experience. We report three lines of research, focusing on the processing of spatial frequencies, unpleasant information, and time-event structure that suggest that impairments occur at both the unconscious and conscious level. We argue that focusing on unconscious, physiological and automatic processing of information in patients, while contrasting that processing with conscious processing, is a first required step before understanding how distortions or other impairments emerge at the conscious level. We then indicate that the phenomenological tradition of psychiatry supports a similar claim and provides a theoretical framework helping to understand the relationship between the impairments and clinical symptoms. We base our argument on the presence of disorders in the minimal self in patients with schizophrenia. The minimal self is tacit and non-verbal and refers to the sense of bodily presence. We argue this sense is shaped by unconscious processes, whose alteration may thus affect the feeling of being a unique individual. This justifies a focus on unconscious mechanisms and a distinction from those associated with consciousness.

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Co-administration of atypical antipsychotics and antidepressants disturbs contrast detection in schizophrenia

Cited by 8 publications

References 20 publications

Contrast sensitivity deficits in schizophrenia: A psychophysical investigation

Contrast sensitivity deficits in schizophrenia: A psychophysical investigation

Schizophrenia and the eye

Is Schizophrenia a Disorder of Consciousness? Experimental and Phenomenological Support for Anomalous Unconscious Processing

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