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Biomedical subjects

K H Nuechterlein

Publications and source records attributed to K H Nuechterlein.

At least 19 recordsLinked to original sources
PubMed2003

Forward and backward visual masking in schizophrenia: influence of age.

BACKGROUND: Visual masking tasks assess the earliest stages of visual processing. This study was conducted to address: (1) whether schizophrenia patients show masking deficits after controlling for sensory input factors; (2) whether patients have relatively intact forward masking (when the mask precedes the target) compared with backward masking (when the mask follows the target); and (3) whether the masking deficits in schizophrenia reflect an accelerated age-related decline in performance. METHOD: A staircase method was used to ensure that the unmasked target identification was equivalent across subjects to eliminate any confounding due to differences in discrimination of simple perceptual inputs. Three computerized visual masking tasks were administered to 120 schizophrenia patients (ages 18-56) and 55 normal comparison subjects (ages 19-54) under both forward and backward masking conditions. The tasks included: (1) locating a target; (2) identifying a target with a high-energy mask; and (3) identifying a target with a low-energy mask. RESULTS: Patients showed deficits across all three masking tasks. Interactions of group by forward versus backward masking were not significant, suggesting that deficits in forward and backward masking were comparable. All three conditions showed an age-related decline in performance and rates of decline were comparable between patients and controls. Two of the masking conditions showed increased rates of decline in backward, compared to forward, masking. CONCLUSIONS: We found age-related decline in performance that was comparable for the two groups. In addition, we failed to find evidence of a relative sparing of forward masking in schizophrenia. These results suggest that: (1) early visual processing deficits in schizophrenia are not due to a simple perceptual input problem; (2) sustained channels are involved in the masking deficit (in addition to transient channels); and (3) for the age range in this study, these deficits in schizophrenia are not age-related.

Adolescent↗
PubMed2001

Age-related changes in frontal and temporal lobe volumes in men: a magnetic resonance imaging study.

BACKGROUND: Imaging and postmortem studies provide converging evidence that, beginning in adolescence, gray matter volume declines linearly until old age, while cerebrospinal fluid volumes are stable in adulthood (age 20-50 years). Given the fixed volume of the cranium in adulthood, it is surprising that most studies observe no white matter volume expansion after approximately age 20 years. We examined the effects of the aging process on the frontal and temporal lobes. METHODS: Seventy healthy adult men aged 19 to 76 years underwent magnetic resonance imaging. Coronal images focused on the frontal and temporal lobes were acquired using pulse sequences that maximized gray vs white matter contrast. The volumes of total frontal and temporal lobes as well as the gray and white matter subcomponents were evaluated. RESULTS: Age-related linear loss in gray matter volume in both frontal (r = -0.62, P<.001) and temporal (r = -0.48, P<.001) lobes was confirmed. However, the quadratic function best represented the relationship between age and white matter volume in the frontal (P<.001) and temporal (P<.001) lobes. Secondary analyses indicated that white matter volume increased until age 44 years for the frontal lobes and age 47 years for the temporal lobes and then declined. CONCLUSIONS: The changes in white matter suggest that the adult brain is in a constant state of change roughly defined as periods of maturation continuing into the fifth decade of life followed by degeneration. Pathological states that interfere with such maturational processes could result in neurodevelopmental arrests in adulthood.

Adult↗
PubMed2001

Schizophrenia and schizophrenia-spectrum personality disorders in the first-degree relatives of children with schizophrenia: the UCLA family study.

BACKGROUND: This study tested the hypothesis that childhood-onset schizophrenia (COS) is a variant of adult-onset schizophrenia (AOS) by determining if first-degree relatives of COS probands have an increased risk for schizophrenia and schizotypal and paranoid personality disorders. METHODS: Relatives of COS probands (n = 148) were compared with relatives of attention-deficit/hyperactivity disorder (ADHD) (n = 368) and community control (n = 206) probands. Age-appropriate structured diagnostic interviews were used to assign DSM-III-R diagnoses to probands and their relatives. Family psychiatric history was elicited from multiple informants. Diagnoses of relatives were made blind to information about probands' diagnoses. Final consensus diagnoses, which integrated family history, direct interview information, and medical records, are reported in this article. RESULTS: There was an increased lifetime morbid risk for schizophrenia (4.95% +/- 2.16%) and schizotypal personality disorder (4.20% +/- 2.06%) in the parents of COS probands compared with parents of ADHD (0.45% +/- 0.45%, 0.91% +/- 0.63%) and community control (0%) probands. The parents of COS probands diagnosed as having schizophrenia had an early age of first onset of schizophrenia. Risk for avoidant personality disorder (9.41% +/- 3.17%) was increased in the parents of COS probands compared with parents of community controls (1.67% +/- 1.17%). CONCLUSIONS: The psychiatric disorders that do and do not aggregate in the parents of COS probands are remarkably similar to the disorders that do and do not aggregate in the parents of adults with schizophrenia in modern family studies. These findings provide compelling support for the hypothesis of etiological continuity between COS and AOS.

Adolescent↗
PubMed2001

Attentional characteristics of schizophrenia patients differing in learning proficiency on the Wisconsin Card Sorting Test.

The Wisconsin Card Sorting Test (WCST), a test of concept formation, was given to 49 schizophrenia inpatients in three blocks of 64 cards each with the second block comprising special instructions and trial-by-trial feedback. With the help of a psychometric algorithm based on linear regression analysis, the patients were classified according to their response to these specific interventions. Results yielded 15 high scorers, 23 learners, and 11 nonlearners. This a priori classification was confirmed by cluster analysis. Next, these groups were further analyzed with the Degraded Stimulus Continuous Performance Test (DS-CPT), a test of target discrimination, and the Test of Attentional Style (TAS), which assesses habitual, subjectively experienced attentional problems. A significant difference between high scorers and nonlearners was found for discriminative sensitivity (d'), with the learners achieving intermediate scores. Results for only the DS-CPT response criterion (beta) and a TAS subscale (Distractibility) tended to be significant. Discriminant analysis also revealed that d' is the most powerful variable for discriminating among the subgroups. The article also addresses baseline versus dynamic assessment, specific rehabilitation needs in subgroups of schizophrenia patients different in learner status, and the neurocognitive characteristics of the subgroups.

Adult↗
PubMed2001

Thought disorder in attention-deficit hyperactivity disorder.

OBJECTIVE: This study compared thought disorder and associated cognitive variables in attention-deficit hyperactivity disorder (ADHD) and schizophrenia. METHOD: Speech samples of 115 ADHD, 88 schizophrenic, and 190 normal children, aged 8 to 15 years, were coded for thought disorder. A structured psychiatric interview, the WISC-R, the Continuous Performance Test, and the Span of Apprehension task were administered to each child. RESULTS: The ADHD and schizophrenic groups had thought disorder compared with the normal children. However, the subjects with ADHD had a narrower range of less severe thought disorder than did the schizophrenic subjects. The younger children with ADHD and schizophrenia had significantly more thought disorder than did the older children with these diagnoses. IQ, attention, and working memory were associated with thought disorder in the ADHD but not the schizophrenic group. CONCLUSIONS: Thought disorder in childhood is not specific to schizophrenia and reflects impaired development of children's communication skills.

Adolescent↗
PubMed2001

Family transactions and relapse in bipolar disorder.

This study examined whether patient symptoms and relatives' affective behavior, when expressed during directly observed family interactions, are associated with the short-term course of bipolar disorder. Twenty-seven bipolar patients and their relatives participated in two 10-minute family interactions when patients were discharged after a manic episode. Results indicated that patients who showed high levels of odd and grandiose thinking during the interactions were more likely to relapse during a 9-month followup period than patients who did not show these symptoms during the family discussions. Relapse was also associated with high rates of harshly critical and directly supportive statements by relatives. Patients' odd thinking and relatives' harsh criticism were significantly more likely to be correlated when patients relapsed (r = .53) than when they did not relapse (r = .12). Results suggest that bipolar patients who show increased signs of residual symptomatology during family transactions during the post-hospital period are at increased relapse risk. The data also suggest that relatives of relapsing patients cope with these symptoms by increasing both positive and negative affective behaviors. Moreover, a bidirectional, interactional relationship between patients' symptoms and relatives' coping style seems to capture best the role of the family in predicting relapse in bipolar disorder.

Adaptation, Psychological↗
PubMed2001

Attentional stages of information processing during a continuous performance test: a startle modification analysis.

This study of 31 college students employed the startle eye-blink modification (SEM) technique to index both early and later stages of attentional processing during a memory-load version of the Continuous Performance Test (CPT). Participants viewed a series of digits and pressed a button after the digit 7 of each 3-7 sequence. A startling noise burst was presented either 120 or 1,200 ms following three preselected prepulses: target (3), nontarget (non-3 and non-7 digits), or target plus distractor (3 and simultaneous tone distractor). Greater startle inhibition occurred 120 ms following target and target-plus-distractor prepulses compared with nontargets, indicating early selective attention. No difference was observed between SEM during target and target-plus-distractor prepulses, suggesting the distractor was effectively ignored. At 1,200 ms, the three prepulse types produced nondifferential inhibition, suggesting that modality-specific selective attention occurs in anticipation of the presentation of the next CPT prepulse. These findings indicate that SEM distinguishes between different early selective attention and later anticipatory attention subprocesses underlying the CPT.

Adolescent↗
PubMed2000

Symptom dimensions in recent-onset schizophrenia and mania: a principal components analysis of the 24-item Brief Psychiatric Rating Scale.

Previous four- and five-factor solutions of the 18-item Brief Psychiatric Rating Scale (BPRS) suggested the possibility of an affective dimension in psychosis. A principal components analysis was used to analyze psychiatric symptom data rated on an expanded 24-item version of the BPRS. BPRS data were collected during a period of acute psychotic and affective illness with 114 young adult, recent-onset schizophrenia and schizoaffective patients and 27 bipolar manic patients. Principal components analyses of the 18-item and 24-item BPRS indicated a four-factor solution was the most interpretable. Principal components analysis of the 24-item BPRS produced a clear mania factor characterized by high loadings from items added to the 18-item BPRS, which included elevated mood, motor hyperactivity, and distractibility. This factor solution suggests that the 24-item BPRS allows for an expanded assessment of affective symptoms relating to a manic dimension. Potentially important symptoms that were added to the traditional 18-item version, namely suicidality, bizarre behavior, and self-neglect, also make clear contributions to other factors.

Adult↗
PubMed2000

On the clinical and cognitive meaning of impaired sensorimotor gating in schizophrenia.

Schizophrenia patients have been shown to have a defective sensorimotor gating process as indexed by impaired prepulse inhibition of the startle eyeblink reflex. Moreover, we have previously reported that schizophrenia patients have dysfunctional attentional modulation of prepulse inhibition. The present experiment combined our previous sample of 14 schizophrenia outpatients and 12 demographically matched control subjects with a new sample of 10 outpatients and 6 control subjects. All participants performed a tone-length judgement task that involved attending to one pitch of tone (the attended prepulse) and ignoring another pitch of tone (the ignored prepulse). During this task the acoustic startle eyeblink reflex was electromyographically recorded from the orbicularis oculi muscle. The results replicated the finding of impaired attentional modulation of prepulse inhibition in the new sample of schizophrenia outpatients compared to demographically matched control subjects. Specifically, the new control group exhibited greater startle modification during the attended prepulse, whereas the new patient group failed to show this differential effect. In addition, impaired prepulse inhibition following the attended prepulse was significantly correlated with heightened delusions, conceptual disorganization, and suspiciousness as measured with the expanded Brief Psychiatric Rating Scale. These correlations were significant with prepulse inhibition to the attended prepulse but not with prepulse inhibition to the ignored prepulse. Impaired prepulse inhibition was not correlated with negative symptoms. All in all, the results support the hypothesis that impaired attentional modulation of startle prepulse inhibition reflects basic neurocognitive processes related to thought disorder in schizophrenia.

Acoustic Stimulation↗
PubMed2000

MMPI discriminators of deficit vs. non-deficit recent-onset schizophrenia patients.

Seventy-four patients with a recent initial onset of schizophrenia were studied during an inpatient hospitalization for a recent onset of schizophrenia as well as during a 12-month period of outpatient treatment as part of a large longitudinal study at UCLA. The Proxy for the Deficit Syndrome (PDS; Kirkpatrick, B., Buchanan, R.W., Carpenter, W.T., 1993. Case identification and stability of the deficit syndrome of schizophrenia. Psychiatry Research 47, 47-56.) was calculated based on psychiatric symptoms rated on the Brief Psychiatric Rating Scale every 2 weeks throughout the 12 months. The Minnesota Multiphasic Personality Inventory (MMPI) was administered to the schizophrenia patients at the index hospitalization. The 168-item version of the MMPI (MMPI-168) was administered at the baseline point of the 12-month period of outpatient treatment, and again 1 year later. Normal comparison subjects were tested with the MMPI or MMPI-168 at comparable time intervals. The UCLA Social Attainment Scale, a measure of the adequacy of social functioning and relatedness, was examined at the outpatient baseline and 12-month points. During the outpatient period, the Deficit Schizophrenia group (i.e. schizophrenia patients with high 12-month average PDS scores) had lower T-scores than the Non-deficit Schizophrenia group on several MMPI-168 scales, especially scales related to affective distress and anxiety. The MMPI-168 scores of normal subjects were generally the lowest of the three groups, but not always significantly lower than those of the Deficit Schizophrenia group. Social functioning at the end of the 12-month period was worst for the patient group with high deficit (PDS) scores. The findings are congruent with the concept of a Deficit Syndrome for which the PDS is the proxy.

Acute Disease↗
PubMed2000

Neurocognitive vulnerability, interpersonal criticism, and the emergence of unusual thinking by schizophrenic patients during family transactions.

BACKGROUND: This study examined whether the combination of patients' neurocognitive deficits and criticism by others would predict the emergence of patients' unusual thinking during stressful family transactions. METHODS: When clinically stable, 41 patients with recent-onset schizophrenia completed 2 versions of a visual vigilance task, the Continuous Performance Test (CPT). One CPT emphasized early perceptual processing, while the other stressed immediate, working memory. On a separate occasion, patients and family members participated in a 20-minute interaction in which the number of relatives' criticisms and patients' unusual thoughts was assessed. RESULTS: In a hierarchical regression model, after entering performance on the CPT demanding immediate, working memory, and the number of criticisms by family members, the interaction of CPT performance and criticism significantly predicted the number of patients' unusual thoughts during the family session (r(2) change = 0.09; P =.03). Post hoc analyses revealed that the number of criticisms and odd thoughts correlated significantly (r = 0.59, P =. 03) for patients who had poor memory-load CPT performance, but were unrelated (r = -0.07) for patients who did well on the memory-load CPT. The CPT emphasizing early visual processing, either alone or in combination with interpersonal criticism, did not predict the number of patients' unusual thoughts during the interaction. CONCLUSION: The results suggest that the combination of patients' working memory deficits and interpersonal criticism jointly predicts psychotic thinking, consistent with a model of schizophrenia that emphasizes the interaction of neurocognitive vulnerability and psychosocial stress factors. Arch Gen Psychiatry. 2000;57:1174-1179.

Adolescent↗
PubMed2000

Fluphenazine levels during maintenance treatment of recent-onset schizophrenia: relation to side effects, psychosocial function and depression.

RATIONALE: The utility of fluphenazine levels during maintenance treatment of schizophrenia is still unclear. OBJECTIVES: This study investigated the relationship between fluphenazine levels and a variety of clinical measures during maintenance treatment of schizophrenia. METHODS: Fluphenazine levels, side effects, depression and psychosocial outcome were measured at five time points over approximately 1 year in 59 recent onset schizophrenic patients treated with a maintenance dose of injectable fluphenazine decanoate. Negative symptoms were evaluated at the 1-year endpoint. RESULTS: Fluphenazine levels showed marked intraindividual variability even when measurements were restricted to the second 6 months of treatment, by which time steady state levels should have been achieved. No consistent relationship was found between fluphenazine levels and any of the outcome measures. CONCLUSIONS: The results of this study suggest that fluphenazine plasma levels do not routinely add relevant clinical information beyond that of dose in evaluating potential side effects or negative consequences during maintenance treatment with the decanoate form of the medication.

Adult↗
PubMed2000

Attention in HIV-infected children: results from the Hemophilia Growth and Development Study.

Attentional functioning was examined in three groups of 7- to 19-year-old male participants with hemophilia: (1) HIV seronegative controls (HIV-, N = 66), (2) HIV seropositive participants with CD4+ lymphocyte counts greater than or equal to 200 (HIV+ CD4+ > or = 200, N = 79), and (3) severely immune suppressed HIV seropositive participants (HIV+ CD4+ < 200, N = 28). Two measures sensitive to attention deficits were used: the Continuous Performance Test (CPT) and the Span of Apprehension (Span). On the CPT, there was a decrement in attention in both HIV+ groups, as indexed by an increase in false alarm rate from Block 1 to Block 3, that was not present in the HIV- group. The longer the HIV+ children were required to sustain attention to the CPT, the more they responded to the incorrect stimulus. This effect decreased as age increased. Span percent correct and latency to correct were associated with the presence of a premorbid history of intracerebral hemorrhage, but were not sensitive to HIV status or degree of immune suppression in the HIV+ children, suggesting morbidity related to hemophilia. The remaining CPT and Span variables--hit rate, sensitivity, latency, percent correct, and latency to correct--showed the expected associations with age, but none showed conclusive associations with HIV status or immune suppression in the HIV+ participants.

Adolescent↗
PubMed2000

Controllability perceptions and reactions to symptoms of schizophrenia: a within-family comparison of relatives with high and low expressed emotion.

In a sample of 35 family members of patients with recent-onset schizophrenia, attributions of control and the content of critical comments were compared for 2 relatives of the same household who held discrepant expressed emotion (EE) attitudes (1 high and 1 low) toward their mentally ill family member. Attributions and the content of critical comments were also compared for low-EE relatives from low-EE homes versus low-EE relatives from high-EE homes. Our results indicate that high-EE relatives tend to attribute more control over behavior to patients than do low-EE relatives of the same patient. In addition, low-EE relatives from high-EE homes attribute more behavioral control to patients than do low-EE relatives from low-EE homes. These findings suggest that EE status is linked to attributions of control over behaviors, but additional patient factors or influences among family members may also affect EE attitudes.

Acute Disease↗
PubMed2000

A comparison of psychiatric symptoms between Anglo-Americans and Mexican-Americans with schizophrenia.

Culture is widely thought to influence the form, content, and extent of symptoms experienced and expressed by the mentally ill. However, little is known about how specific cultural groups differ in their symptomatic presentation of mental illness. Using data derived from the Present State Exam, the current study compared 63 Anglo-American and 53 Mexican-American patients with schizophrenia on ten psychiatric symptoms. A series of logistic regressions offered several interesting findings. For instance, as hypothesized, Mexican-American patients were more likely to report physical symptoms than their Anglo-American counterparts. Also in line with expectations, Anglo-American patients reported experiencing a greater frequency of several psychiatric symptoms such as persecutory delusions, nervous tension, and blunted affect. Results from this study suggest that the presentation of even a very biologically determined disorder such as schizophrenia can be shaped by sociocultural factors. Specific aspects of Anglo-American and Latino cultures that may influence symptom patterns in patients suffering from schizophrenia are discussed.

Adolescent↗
PubMed2000

Life events can trigger depressive exacerbation in the early course of schizophrenia.

Previous studies have linked life events with depression in chronic schizophrenia, but those studies had methodological limitations. Using a prospective research design and examining events that were clearly independent of the patients' illnesses, the authors sought to determine whether stressful life events could trigger depressive symptoms in the early course of schizophrenia. Schizophrenia patients (n = 99) were followed for 1 year from a point of outpatient stabilization. Life event interviews were conducted every 4 weeks and symptom assessments every 2 weeks. Survival analyses showed a significantly increased risk for an exacerbation of significant depressive symptoms following an independent life event. Of interest is that an analysis of competing risk showed that the odds of psychotic exacerbation following a major independent life event were not significantly greater than the odds of depressive exacerbation. The risk of depression and of psychosis after experiencing a stressful life event is significantly increased for the first month, but the risk period can extend to 3 months.

Acute Disease↗
PubMed1999

Continuous-processing related ERPS in adult schizophrenia: continuity with childhood onset schizophrenia.

BACKGROUND: Previous work with schizophrenic children disclosed deficits on two continuous performance tests (CPTs) and ERP indices of reduced attentional resource allocation. METHODS: The two CPTs were administered to adult schizophrenics and matched control subjects. The simple CPT required only that the subject respond whenever the target digit was displayed. The complex version required a response whenever any digit was displayed on two successive trials. Event-related potentials (ERPs) were recorded during task performance. RESULTS: Schizophrenics had fewer hits on both CPT versions, showed a greater drop in performance from the simple to the complex CPT, and took longer to respond than controls. The processing negativity (Np) showed a greater amplitude increase from nontarget to target in normals than in schizophrenics, and the overlapping P2 component was more negative in normals. P3 latency was longer in schizophrenics, but P3 amplitude did not differ. CONCLUSIONS: Group performance and processing negativity effects replicated those from an earlier study of schizophrenic and normal children administered the same versions of the CPT, suggesting similar abnormalities in the allocation and modulation of information processing resources.

Adult↗