Defining the schizophrenia phenotype

Thaker, Gunvant K.

doi:10.1007/s11920-000-0022-6

Cited by 16 publications

(8 citation statements)

References 89 publications

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“…Healthy individuals with elevated scores on the PhysAn scale also show many attributes of a high-risk population: they have an increased incidence of the cognitive, behavioral, and social abnormalities associated with schizophrenia, including impaired attention (Jutai, 1989;Wilkins and Venables, 1992;Erlenmeyer-Kimling et al, 1993), reaction time crossover (Simons, 1982), abnormal P300 amplitude (Miller, 1986), skin conductance nonresponsiveness (Dawson and Nuechterlein, 1984), and poorer social competence (Garnet et al, 1993;Blanchard et al, 1998). Further, PhysAn scores may have a familial component as they are higher in schizophrenic patients and their relatives than controls (Katsanis et al, 1990;Clementz et al, 1991;Franke et al, 1993), and are higher in individuals with schizophrenia-related personality disorders who have a genetic loading of schizophrenia than in those without it (Thaker, 2000).…”

Section: Subjectsmentioning

confidence: 99%

Stress-Induced Dopamine Release in Humans at Risk of Psychosis: a [11C]Raclopride PET Study

Soliman

O’Driscoll

Pruessner

et al. 2007

Neuropsychopharmacol

133

109

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Drugs that increase dopamine levels in the brain can cause psychotic symptoms in healthy individuals and worsen them in schizophrenic patients. Psychological stress also increases dopamine release and is thought to play a role in susceptibility to psychotic illness. We hypothesized that healthy individuals at elevated risk of developing psychosis would show greater striatal dopamine release than controls in response to stress. Using positron emission tomography and [ 11 C]raclopride, we measured changes in synaptic dopamine concentrations in 10 controls and 16 psychometric schizotypes; 9 with perceptual aberrations (PerAb, ie positive schizotypy) and 7 with physical anhedonia (PhysAn, ie negative schizotypy). [ 11 C]Raclopride binding potential was measured during a psychological stress task and a sensory-motor control. All three groups showed significant increases in self-reported stress and cortisol levels between the stress and control conditions. However, only the PhysAn group showed significant stress-induced dopamine release. Dopamine release in the entire sample was significantly negatively correlated with smooth pursuit gain, an endophenotype linked to frontal lobe function. Our findings suggest the presence of abnormalities in the dopamine response to stress in negative symptom schizotypy, and provide indirect evidence of a link to frontal function.

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Section: Subjectsmentioning

confidence: 99%

Stress-Induced Dopamine Release in Humans at Risk of Psychosis: a [11C]Raclopride PET Study

Soliman

O’Driscoll

Pruessner

et al. 2007

Neuropsychopharmacol

133

109

View full text Add to dashboard Cite

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“…Questions still remain as to whether the psychophysiologic deficits in SPD subjects are secondary to the clinical symptoms, the familial relationship to schizophrenia, or both [29].…”

Section: Psychophysiologic Measuresmentioning

confidence: 99%

How does studying schizotypal personality disorder inform us about the prodrome of schizophrenia?

Seeber

Cadenhead

2005

Curr Psychiatry Rep

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An increasing emphasis in the schizophrenia literature has been on the prodromal phase of the illness. The study of schizophrenia spectrum illness, including schizotypal personality disorder, has added important insight into the etiology, neuropathology, and treatment of schizophrenia, which can facilitate early identification, intervention, and perhaps prevention of the illness. The heterogeneity of the schizophrenia spectrum makes its definition elusive at best. The primary aim of the Cognitive Assessment and Risk Evaluation Program at the authors' institution is to combine the current knowledge of clinical and demographic risk factors for schizophrenia with the rapidly emerging data on vulnerability markers, or endophenotypes, that are associated with schizophrenia. The use of brain-based vulnerability markers may help to identify neurobiologically and clinically meaningful subgroups within this heterogeneous population of individuals in the early stages of schizophrenia. Another important aim of the Cognitive Assessment and Risk Evaluation program is to thoroughly assess those individuals who have not converted to psychosis to understand potential protective factors, reduce the rate of false positives, and decrease disability. The current review details a strategy for researching the schizophrenia prodrome by using information gained from research in schizotypal personality disorder.

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“…The diagnostic boundaries of psychotic disorders including schizophrenia (SCZ)-spectrum disorders and psychotic bipolar disorder (BD-P) are increasingly recognized as more porous than traditionally depicted in diagnostic systems (Thaker, 2000). Identifying distinctive and shared features of these disorders can help to inform psychiatric classification and to understand factors that contribute to their overlapping symptoms (Carpenter, 2014).…”

Section: Introductionmentioning

confidence: 99%

Emotion recognition deficits in schizophrenia-spectrum disorders and psychotic bipolar disorder: Findings from the Bipolar-Schizophrenia Network on Intermediate Phenotypes (B-SNIP) study

Ruocco

Reilly

Rubin

et al. 2014

Schizophrenia Research

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Background Difficulty recognizing facial emotions is an important social-cognitive deficit associated with psychotic disorders. It also may reflect a familial risk for psychosis in schizophrenia-spectrum disorders and bipolar disorder. Objective The objectives of this study from the Bipolar-Schizophrenia Network on Intermediate Phenotypes (B-SNIP) consortium were to: 1) compare emotion recognition deficits in schizophrenia, schizoaffective disorder and bipolar disorder with psychosis, 2) determine the familiality of emotion recognition deficits across these disorders, and 3) evaluate emotion recognition deficits in nonpsychotic relatives with and without elevated Cluster A and Cluster B personality disorder traits. Method Participants included probands with schizophrenia (n=297), schizoaffective disorder (depressed type, n=61; bipolar type, n=69), bipolar disorder with psychosis (n=248), their first-degree relatives (n=332, n=69, n=154, and n=286, respectively) and healthy controls (n=380). All participants completed the Penn Emotion Recognition Test, a standardized measure of facial emotion recognition assessing four basic emotions (happiness, sadness, anger and fear) and neutral expressions (no emotion). Results Compared to controls, emotion recognition deficits among probands increased progressively from bipolar disorder to schizoaffective disorder to schizophrenia. Proband and relative groups showed similar deficits perceiving angry and neutral faces, whereas deficits on fearful, happy and sad faces were primarily isolated to schizophrenia probands. Even non-psychotic relatives without elevated Cluster A or Cluster B personality disorder traits showed deficits on neutral and angry faces. Emotion recognition ability was moderately familial only in schizophrenia families. Conclusions Emotion recognition deficits are prominent but somewhat different across psychotic disorders. These deficits are reflected to a lesser extent in relatives, particularly on angry and neutral faces. Deficits were evident in non-psychotic relatives even without elevated personality disorder traits. Deficits in facial emotion recognition may reflect an important social-cognitive deficit in patients with psychotic disorders.

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Defining the schizophrenia phenotype

Cited by 16 publications

References 89 publications

Stress-Induced Dopamine Release in Humans at Risk of Psychosis: a [11C]Raclopride PET Study

Stress-Induced Dopamine Release in Humans at Risk of Psychosis: a [11C]Raclopride PET Study

How does studying schizotypal personality disorder inform us about the prodrome of schizophrenia?

Emotion recognition deficits in schizophrenia-spectrum disorders and psychotic bipolar disorder: Findings from the Bipolar-Schizophrenia Network on Intermediate Phenotypes (B-SNIP) study

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