Biologic Heterogeneity and Psychiatric Research

Buchsbaum, Monte S.; Rieder, Ronald O.

doi:10.1001/archpsyc.1979.01780110017001

Cited by 140 publications

(16 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Heterogeneity is a major obstacle in identi fying the biologic basis of disease [7], Studies attempting to identify the biochemical events mediating antidepressant effect require a ho mogenous patient group. Pattern analysis may identify a more homogenous group of drug responders than end-point analysis.…”

Section: Resultsmentioning

confidence: 99%

Review of the Use of Pattern Analysis to Differentiate True Drug and Placebo Responses

Rothschild¹,

Quitkin²

1992

Psychother Psychosom

View full text Add to dashboard Cite

Placebo response in patients assigned active drug is a troubling source of variance in antidepressant studies. This paper summarizes a series of studies utilizing pattern analysis to distinguish between placebo and true drug responses. Analysis of the persistence, speed, and timing of onset of patients’ improvement during antidepressant therapy reveals distinct patterns of response which are likely to be attributable to placebo and true drug effects. While true drug effects seem to be characterized by a 2-week delay in onset followed by persistent improvement, placebo effects seem to be characterized by abrupt, transient improvement. Gradual responses on placebo may be due to spontaneous remission. The heuristic and clinical implications of pattern analysis are discussed.

show abstract

Section: Resultsmentioning

confidence: 99%

Review of the Use of Pattern Analysis to Differentiate True Drug and Placebo Responses

Rothschild¹,

Quitkin²

1992

Psychother Psychosom

View full text Add to dashboard Cite

show abstract

“…In contrast, patients who performed abnormally on the screening tests of attention and perception showed more generalized WM and cognitive deficits. Importantly, between-group comparisons of patients and NC that do not take into account heterogeneity in perceptual encoding ability result in two related inaccuracies: underestimating the magnitude of the encoding deficit in the subgroup with impaired encoding and overestimating it in the group as a whole (Buchsbaum and Rieder, 1979, Coleman et al, 2010). …”

Section: Discussionmentioning

confidence: 99%

The effects of perceptual encoding on the magnitude of object working memory impairment in schizophrenia

Coleman

Krastoshevsky

et al. 2012

Schizophrenia Research

View full text Add to dashboard Cite

Deficits in the visual working memory (WM) system have been consistently reported in schizophrenia patients, but the relative contribution of initial perceptual encoding to these deficits remains unsettled. We assessed the role of visual perceptual encoding on performance on an object WM task. Schizophrenia patients (N=37) and nonpsychiatric control subjects (N=33) were tested on an object WM task involving three delay periods: 200 msec, 3 sec, and 10 sec. Schizophrenia patients performed significantly less accurately than controls on all three conditions. However, after controlling for the effect of perceptual encoding (accuracy on the 200 msec delay condition) on performance in the two memory load conditions, schizophrenia patients demonstrated intact WM in the 3 sec delay condition, and showed a weak trend for decreased accuracy on the 10 sec delay compared with controls. Analysis of individual differences in pattern of performance revealed that a distinct subgroup of poor encoder patients had a significantly greater reduction in accuracy at 3 sec than the other patient subgroups and controls. In contrast, among schizophrenia patients who performed poorly on the 10 sec delay, accuracy was equivalently reduced independent of encoding ability. WM deficits in controls were independent of encoding ability at both delay intervals. These results indicate that encoding ability titrates the magnitude of WM impairment in schizophrenia patients but not in controls, and that heterogeneity has to be taken into account to correctly estimate the effects of perceptual encoding on visual object WM deficits in schizophrenia.

show abstract

“…Thus, an advantage of global measures of ETD, in addition to their greater sensitivity to between-group differences, is that they can be used to take into account the within-group heterogeneity in ways that specific measures often do not or cannot [see (Gibbons et al 1984; Levy et al 1993) for detailed discussions of the use of mixture analysis to resolve within-group heterogeneity; see (Levy et al 2000) for an example of how global and specific measures can be used in tandem to clarify the nature of within-group heterogeneity; see (Buchsbaum and Rieder 1979) for a discussion of the impact of heterogeneity on traditional between-group comparisons].…”

Section: Characterization Of Etdmentioning

confidence: 99%

Eye Tracking Dysfunction in Schizophrenia: Characterization and Pathophysiology

Levy

Sereno

Gooding

et al. 2010

Current Topics in Behavioral Neurosciences

125

View full text Add to dashboard Cite

Eye tracking dysfunction (ETD) is one of the most widely replicated behavioral deficits in schizophrenia and is over-represented in clinically unaffected first-degree relatives of schizophrenia patients. Here, we provide an overview of research relevant to the characterization and pathophysiology of this impairment. Deficits are most robust in the maintenance phase of pursuit, particularly during the tracking of predictable target movement. Impairments are also found in pursuit initiation and correlate with performance on tests of motion processing, implicating early sensory processing of motion signals. Taken together, the evidence suggests that ETD involves higher-order structures, including the frontal eye fields, which adjust the gain of the pursuit response to visual and anticipated target movement, as well as early parts of the pursuit pathway, including motion areas (the middle temporal area and the adjacent medial superior temporal area). Broader application of localizing behavioral paradigms in patient and family studies would be advantageous for refining the eye tracking phenotype for genetic studies.

show abstract

Biologic Heterogeneity and Psychiatric Research

Cited by 140 publications

References 29 publications

Review of the Use of Pattern Analysis to Differentiate True Drug and Placebo Responses

Review of the Use of Pattern Analysis to Differentiate True Drug and Placebo Responses

The effects of perceptual encoding on the magnitude of object working memory impairment in schizophrenia

Eye Tracking Dysfunction in Schizophrenia: Characterization and Pathophysiology

Contact Info

Product

Resources

About