Saturday, September 27, 2008
2:45pm-4:15pm
Paper Session III
1. Longitudinal Analysis of Attentional Deficits in First-Episode Schizophrenia: Probing Structural Processing Bottlenecks Over Time
Authors: 1. Keith Nuechterlein [UCLA]
2. Harold Pashler [UCSD]
3. Kenneth Subotnik [UCLA]
4. Joseph Ventura [UCLA]
Dual-task methods that we have adapted from cognitive psychology allow isolation of the specific types of cognitive processes that individuals are unable to complete simultaneously. These methods, which are variants of the psychological refractory period paradigm, allow the nature of attentional limitations in schizophrenia to be probed in much more precise ways than typical attentional tasks using in clinical research. We have separately manipulated perceptual, response selection, and response production processes to evaluate the location and extent of such structural processing bottlenecks. The current analyses examine results for assessment of first-episode schizophrenia patients at an outpatient baseline point and one year later, compared to longitudinally assessed healthy comparison subjects. Results indicate that the extent of dual-task interference as a function of task temporal overlap is greater in first-episode schizophrenia than in comparison subjects and that this effect is maintained over the one-year period. Furthermore, manipulating the length of response selection processes leads to interference with dual-task performance in first-episode schizophrenia that is consistent with a central structural bottleneck at both points in time. These results indicate that exaggerated interference at the response selection stage is a key source of the divided attention deficits in schizophrenia that is maintained well after the initial psychotic episode is resolved.
2. Do Patients With Schizophrenia Have Chronic Multi-Year Psychotic Activity: A 26 Year Multi-Followup Study
Authors: 1. Martin Harrow [Dept of Psychiatry, University of Illinois at Chicago]
2. Thomas Jobe [Dept of Psychiatry, University of Illinois at Chicago]
3. Linda Grossman [Dept of Psychiatry, University of Illinois at Chicago]
4. Cherise Rosen [Dept of Psychiatry, University of Illinois at Chicago]
5. Robert Faull [Dept of Psychiatry, University of Illinois at Chicago]
This 26-year prospective longitudinal research was designed 1) to assess whether modern-day patients with schizophrenia have frequent or persistent psychosis many years after acute hospitalization. 2) We also analyzed protective factors which may reduce chronic psychosis in schizophrenia. We assessed 176 patients 7 times over 26 years, include 36 patients with schizophrenia. Using standardized instruments, patients were evaluated at each followup for psychosis, thought disorder-disorganization, work disability, neurocognitive impairments, global recovery and treatment. Hypothesized protective factors were assessed prospectively at index hospitalization. Results and Conclusions: 1)Only 25% of the patients with schizophrenia were psychotic at all followups over the 26 year period. 2)Slightly over half of modern-day schizophrenia patients are vulnerable to frequent or “chronic” psychotic activity after the acute phase.3)However, a subgroup of “good prognosis” schizophrenia patients who discontinued antipsychotics experienced long periods of global recovery. 4)The data on psychosis bear on major hypotheses that hallucinations or anomalous perceptual experiences precipitate delusions. 5) Work disability is linked to multiple factors, rather than only one, including a) psychosis, b) neurocognitive impairment, c) negative symptoms, and d) depression. 6)Internal factors such as good premorbid developmental achievements and favorable prognostic factors are protective, reducing the probability of chronic psychosis (p<.01).
3. Towards A Contextual Understanding of Diminished Expressivity in Schizotypy
Authors: 1. Alex Cohen [Louisiana State University]
Although diminished expressivity is a cardinal negative symptom of schizophrenia-spectrum disorders, fundamental questions about its nature remain unclear. In particular, it is unknown whether diminished expressivity (1) reflects a pan-contextual deficit or whether it occurs only in certain situations, (2) is associated with affective nonresponsivity (i.e., lack of within-individual modulation), and (3) affects “real-world” quality of life. The present study employed acoustic analysis of natural speech across a range of evocative contexts in individuals with psychometrically-defined schizotypy. Subjects were individuals with negative schizotypy (n = 34), positive schizotypy (n = 55) and controls (n = 57) who provided verbalizations of their reactions to affective neutral, pleasant and unpleasant pictures during a laboratory experiment. Negative schizotypy was associated with significantly diminished expressivity across all three conditions and, unexpectedly, normal modulation between neutral, pleasant and unpleasant conditions. In contrast, positive schizotypy was associated with relatively normal expressivity and abnormally low levels of between-condition modulation. Within the schizotypy group, diminished expressivity was associated with impoverished objective quality of social relationships but was relatively unrelated to subjective quality of social relationships. The results are discussed in terms of understanding the emotional deficits of schizotypy within a larger affective science framework.
4. Cortisol Response to a Psychosocial Stressor in Schizophrenia: Blunted, Delayed, or Normal?
Authors: 1. Suzanne King [McGill University]
2. Karene Brenner [University of Montreal]
3. Aihua Liu [McGill University]
4. David P. Laplante [Douglas Hospital Research Centre]
5. Ridha Joober [McGill University]
Background: Patients with schizophrenia may differ from healthy controls by having dysregulated physiological responses to stress. Our objective was to determine the extent to which cortisol reaction can discriminate between controls and schizophrenia patients while controlling for symptom severity, personality, body mass index (BMI) and smoking.
Method: 30 chronic schizophrenia patients and 30 matched controls underwent a modified version of the Trier Social Stress Test (TSST), consisting of public speaking and mental arithmetic. Heart rate, blood pressure, and salivary cortisol were measured repeatedly throughout the TSST. In addition, participants completed the NEO Personality Inventory (NEO-FFI), and were interviewed with the Brief Psychiatric Rating Scale (BPRS).
Results: Both groups had a significant increase in heart rate and mean arterial pressure following the TSST. Results of a logistic regression suggests that patients can be discriminated from controls with a smaller change in cortisol between baseline and 15 minutes post-TSST, controlling for BMI and severity of positive symptoms. There was a trend for lower overall cortisol secretion in patients.
Conclusions: Despite demonstrable effects of the stressor on cardiac measures, schizophrenia patients tend to have smaller acute cortisol reaction to psychosocial stress. The significance of this conclusion for vulnerability-stress models of schizophrenia is discussed.
5. Correlates of Lifetime Work Outcome in Schizophrenia
Authors: 1. Christopher Bowie [Mount Sinai School of Medicine]
2. Philip Harvey [Emory University]
Background: Schizophrenia is associated with limited and underproductive employment.
Methods: Older schizophrenia outpatients (N=79) were assessed for neurocognition, symptoms, functional capacity, and community behavior. Work history was determined by chart review and self-reports using a structured interview. The percentage of time employed during active illness was compared to the premorbid phase of illness.
Results: Subjects had a mean of 8.5 (SD=6.3) years between eligible working age (i.e., 16) and first break. Work productivity during the premorbid period was not associated with work productivity after the first episode (r=-.10, p=.39). Neurocognition and affective symptoms were associated with work productivity throughout the illness. Higher premorbid IQ predicted number of hours in productive employment during the premorbid phase. Disability status predicted hours employed during active illness. The discrepancy between percentage of time employed during the premorbid and active phase illness was predicted by disability and compensation status but was not associated with a discrepancy between premorbid IQ and current global cognition, symptom severity, or course of illness as indexed.
Conclusions: Neurocognition and symptoms were correlated with work skills, but decline in work productivity following the onset of schizophrenia was not predicted by traditional symptoms or neurocognitive impairment in this relatively high functioning group of older community dwelling schizophrenia patients. These retrospective findings support the notion that disability status may serve as a disincentive to seek employment in schizophrenia.