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Biomedical subjects

N I Landrø

Publications and source records attributed to N I Landrø.

At least 19 recordsLinked to original sources
PubMed2006

Neuropsychological test profiles in schizophrenia and non-psychotic depression.

OBJECTIVE: The study examined to what degree schizophrenia is characterized by a neuropsychological (NP) test profile specific in shape and level compared with depression and normal functioning. METHOD: Fifty-three patients with schizophrenia, 45 with non-psychotic depression, and 50 normals were assessed with a comprehensive NP test battery and clinical instruments. NP test scores were factor analyzed into seven composite scores. RESULTS: Schizophrenia patients performed significantly below normals across all seven composite scores, whereas depression patients were impaired in two. Verbal memory was most impaired. Sixty-two percent of schizophrenia patients were moderately or severely impaired, the corresponding figure for depression was 28%. Impairment was moderately associated with IQ level and clinical symptom load in schizophrenia, but not in depression. CONCLUSION: Schizophrenia is characterized by deficits across a wide range of NP functions. Thirty-eight percent of the patients are within normal limits. A mild and limited NP disturbance is apparent in depression.

Adult↗
PubMed2005

General psychopathology is more important for executive functioning than diagnosis.

OBJECTIVE: Impaired executive functioning (EF) has often been reported in patients with major depression or schizophrenia. We hypothesize that the variance in EF is more affected by level of general psychopathology than by diagnosis. METHOD: Forty-three patients with major depression and 47 with schizophrenia were included. EF was measured with Wisconsin Card Sorting Test, Stroop Colour Word Test, Paced Auditory Serial Addition Test, Digits Backwards and Controlled Oral Word Association Test. The level of general psychopathology was measured with Brief Psychiatric Rating Scale - Expanded and Positive and Negative Syndrome Scale, the General psychopathology subscale. RESULTS: The level of general psychopathology predicted more of the variance in EF than diagnosis. In multivariate analyses, the effect of general psychopathology on EF was more robust for adjustment for diagnosis than vice versa. CONCLUSION: Future research on cognitive functioning in psychiatric patients should include level of general psychopathology to avoid overemphasising effects of diagnoses.

Adult↗
PubMed2005

Cortisol level predicts executive and memory function in depression, symptom level predicts psychomotor speed.

OBJECTIVE: On a group level depression is related to hypercortisolism and to psychomotor retardation, executive dysfunction and memory impairment. However, intra-group heterogeneity is substantial. Why some are impaired while others remain in the normal range, is not clear. The present study aims at discerning the relative contribution of present symptom severity and hypercortisolism to impairment in the three domains of cognition. METHOD: Morning saliva cortisol was measured in 26 subjects with recurrent major depression prior to a neuropsychological examination with tests known to be sensitive to cognitive impairment in depression. RESULTS: Cortisol level correlated with executive dysfunction and post-encoding memory deficits, but not with processing speed. Depression level correlated with processing speed. These patterns remained significant after controlling for confounders through partial correlations. CONCLUSION: The association between cortisol and cognition is not an artifact of psychiatric symptom load. High level of saliva cortisol is associated with aspects of cognition that can be dissociated from psychomotor retardation, which is dependent on symptom load.

Adult↗
PubMed2003

Attention profile in schizophrenia compared with depression: differential effects of processing speed, selective attention and vigilance.

OBJECTIVE: The aim of the study is to investigate whether subjects with schizophrenia and major depression display attention deficits for different reasons. METHOD: Subjects with schizophrenia (n = 53), recurrent major depression (n = 50) and normal controls (n = 50) were administered with 11 measures of processing speed, selective attention and vigilance. Indices of basal speed, speeded attention, non-speeded attention and vigilance were computed. RESULTS: Both clinical groups were impaired on all chronometric tests. The schizophrenic subjects were also more impaired on speeded attention compared with basal processing speed. Only the schizophrenics were impaired on the non-speeded measures of selective attention. Compared with the schizophrenics, the depressives showed a decrement in vigilance. CONCLUSION: Reduced performance on attention tests in major depression is because of a non-specific speed reduction and loss of vigilance consistent with lack of effort. In addition to generally impaired processing speed, the schizophrenic subjects exposed a deficit in selective attention, indicating executive dysfunction.

Adult↗
PubMed2001

Honig's model of working memory and brain activation: an fMRI study.

The present study investigated changes in neuronal activation with fMRI related to Honig's model of working memory, which is much less studied compared with other working memory models. In contrast to other studies which have applied recognition procedures, the primary aim with the present study was to examine brain activation when subjects had to continuously recall and forget items held in working memory. The results showed that the mid-ventrolateral frontal cortex was particularly activated in the left hemisphere, whereas the mid-dorsolateral frontal cortex was particularly activated in the right hemisphere during execution of the working memory task. The findings are discussed in relation to process- and domain-specific accounts of working memory.

Adult↗
PubMed2001

Memory deficits in young schizophrenics with normal general intellectual function.

The aim of the present study was to examine different dimensions of memory functioning in young schizophrenics with normal general intellectual abilities. Thirty-three patients with schizophrenia and 33 healthy controls were included in the study. The results suggest that immediate short-term memory is intact, though there emerged a working memory deficit in the schizophrenia group. Deficient encoding of verbal material was observed in some, but not in other, testing conditions. There also seemed to be a retrieval deficit for verbal material in schizophrenia, though no storage deficit was indicated. Impaired memory for non-verbal material was also revealed. These results occurred in a context of intact executive functioning as measured by the Wisconsin Card Sorting Test. The results indicate that temporal and frontal structures, as well as their interconnections, may be compromised in schizophrenia.

Adult↗
PubMed2000

Memory functioning and emotional changes in early phase multiple sclerosis.

Memory functioning and emotional changes were evaluated in 26 early phase multiple sclerosis (MS) patients, as compared with 24 healthy controls. There were no significant differences between the groups with respect to age, education, verbal intelligence, or general visual information processing abilities. The MS group performed significantly below controls on the recognition of nonsense visual stimuli. On most verbal memory test indicators, the MS group did not perform deficiently, but there emerged a between-group difference at trend level on a measure reflecting sensitivity to proactive inhibition. The MS patients reported emotional changes and increased levels of psychological symptoms in several areas. Memory task performance was not significantly correlated with subjective complaints of memory impairment, depressive symptoms, or degree of physical disability. However, subjective complaints of memory impairment were related to depression.

Journal Article↗
PubMed1997

Stability in cognitive dysfunctions in schizophrenic patients.

The purpose of the present study was to classify cognitive dysfunctions in schizophrenic subjects according to a trait/state model. A sample of 15 patients was examined on 10 different cognitive measures in two distinctly different phases: an acute psychotic state and partial remission. To determine the degree of dysfunction at the two stages of illness, the schizophrenic patients were also compared to 14 non-psychiatric controls. Six of the 10 measures examined can be classified as cognitive deficits in schizophrenics. Four measures are possibly trait-dependent components: two backward masking scores and two long-term memory measures. A short-term memory measure is the only one that can be classified as an episode-linked factor. The other cognitive deficits found can be characterized as mediating vulnerability factors, i.e. they are more prominent in the acute psychotic state, but do not completely disappear during remission states.

Adolescent↗
PubMed1997

Memory functioning in patients with primary fibromyalgia and major depression and healthy controls.

Memory functioning was assessed in 25 primary fibromyalgia (FM) patients by comparing them with 22 major depressed patients and 18 healthy controls. A broad range of short- and long-term memory tasks were included. Both major depressed and FM patients were significantly impaired on long-term memory tasks requiring effortful processing, compared to healthy controls. When the depressive status of the fibromyalgia patients was accounted for, only the subsample with a lifetime major depressive disorder showed memory impairment as compared with the healthy controls.

Adult↗
PubMed1995

Memory in schizophrenia and affective disorders.

The purpose of the present study was to investigate the stability of memory and information processing in schizophrenics and affectively disturbed patients. Twenty-two schizophrenics, eight affectives and 14 normal controls were tested twice, with an interval of approximately one year. Results showed that normals performed better than schizophrenics and affectively disturbed patients on almost all of the cognitive measures. The differences reached a level of significance on a reaction time test, a vigilance task and a long-term memory task. The only measure where the difference did not reach a level of significance was on a short-term memory test. Groups' performance to some extent changed over time on most of the measures, but the changes were not significantly different for different groups.

Adult↗
PubMed1995

Information processing in primary fibromyalgia, major depression and healthy controls.

OBJECTIVE: To assess the information processing capabilities in 25 patients with primary fibromyalgia (FM) by comparing them with 22 patients with major depression and 18 healthy controls. METHODS: A broad range of tasks related to various subcomponents of information processing were included. RESULTS: Our results indicated that patients with primary FM in general share with depressives a nonspecific deficit in information processing capacity. However, our data showed that cognitive dysfunction reflecting a presumed compromise of the right hemisphere is present in major depression, but not in primary FM. CONCLUSION: This finding would suggest that primary FM and depression are probably different conditions.

Adult↗
PubMed1994

Mueller-Lyer illusion and size estimation performance in schizophrenics compared to normal controls.

A size estimation (SE) paradigm and the Mueller-Lyer (ML) illusion were used to examine perceptual disturbances in schizophrenics. 35 reliably diagnosed (DSM III-R) schizophrenics were compared to 20 subjects with no history of psychiatric illness. Perceptual distortions found in previous studies of schizophrenics were only to a certain extent confirmed in the present results. More overestimators were found among the schizophrenics than among the normals on the SE task. The schizophrenics, first of all the chronic patients, also proved to be more prone to the Mueller-Lyer illusion. A reason why the very clear differences between schizophrenics and normals found in previous examinations were not confirmed in the present study, might be that a reliable diagnostic instrument was for the first time used in this kind of study.

Adult↗
PubMed1994

Memory function in schizophrenia.

Memory impairment in schizophrenia has been reported in several studies during the last decades. Issues related to the interpretation of such deficits are discussed. Research strongly suggests specific memory dysfunction in schizophrenia that may be neither drug induced nor secondary consequences of attentional disorders. Our own longitudinal data indicate that these deficits deviate from normal function in a relatively stable way. Although medial temporal lobe structures seems to be of special importance, memory function may be vulnerable to a variety of neurobiological abnormalities.

Adult↗
PubMed1993

Memory functioning in chronic and non-chronic schizophrenics, affectively disturbed patients and normal controls.

Memory impairment has been reported among schizophrenics in several studies. There are a number of uncertainties in interpreting such deficits. The present study examined short- and long-term verbal memory in schizophrenic patients (n = 30), affectively distributed patients (n = 18) and normal controls (n = 18). Schizophrenics showed a significant decrease in memory test performance, compared with both normal controls and other psychiatric patients. Chronic schizophrenics seem to be characterized by qualitatively different memory functioning compared with non-chronic subjects. In a free recall task chronic subjects showed significantly decreased performance for the initial (primacy) and final (recency) items. Memory functioning was not correlated with performance on the Wisconsin Card Sorting Test. This could indicate a selective cognitive dysfunction of an amnesic nature in chronic schizophrenics.

Adult↗
PubMed1993

Stability in backward masking performance in schizophrenics, affectively disturbed patients, and normal subjects.

The purpose of the present longitudinal study was to investigate the stability of backward masking performance in schizophrenics and nonschizophrenic psychotic patients. Twenty-two schizophrenics, eight nonschizophrenics, and 14 normal controls were tested three times, with an interval of 1 year between each test session. A standard stimulus duration procedure was used. The relative onset intervals between the target and the mask was 16.5 msec or 33 msec. A no mask condition was presented before the two masking conditions. Results showed that masking performance is a stable phenomenon, for both psychiatric groups and for normal controls. Significant differences were found between schizophrenics and the normal controls, but not between the two psychiatric groups. Vulnerability to masking stimuli as a specific characteristic for schizophrenics is, thus, not supported in the present study. The results suggest that backward masking deficit is an enduring feature of psychotic disturbances.

Adult↗
PubMed1992

Vigilance deficits in schizophrenics and affectively disturbed patients.

Vigilance is a concept associated with the early levels of information processing. Vigilance deficits have repeatedly been found in schizophrenic patients. It has not been clear, however, whether such cognitive dysfunctions are specific to schizophrenics or not. In this study, 28 schizophrenics were compared with 19 affectively disturbed patients and 17 normals on a vigilance test that is a hybridization of a Continuous Performance Test (CPT) and a Span of Apprehension Test (SAT). The results showed that schizophrenics performed significantly below the normals only on target hits on the CPT. There were no differences between the two patient groups, either on number of correct hits or on commission errors. On the SAT measures, normals performed better than the two psychiatric groups on all measures. Schizophrenics had more commission errors than the affectives, but there were no differences between the two groups with respect to target hits. Neither CPT nor SAT deficit, thus, seem to be specific schizophrenic characteristics.

Adult↗
PubMed1990

Information processing: a new model for understanding cognitive disturbances in psychiatric patients.

Information processing models are influenced by the information sciences and by computer technology, which progressed in the 1960s and 1970s. During the last decade these models have formed the theoretical basis for much of the experimental research on cognitive dysfunctions in psychiatric patients. An essential element in all of these models is that information is processed in several discrete stages. Different experimental paradigms have been developed in order to tap information about the processes taking place in each of these stages. Most of the research so far on pathological groups has been done on schizophrenic patients. Some deficits found in schizophrenics seem to be symptom-related. This is the case with performance deficits on the Continuous Performance Test with low processing load. Other dysfunctions might be vulnerability indicators, such as deficit performance on the forced choice Span of Apprehension task and the Continuous Performance Test with high momentary processing load, backward masking, serial recall for items that involve active rehearsal, and eye movement dysfunctions. However, information processing deficits do not seem to be specifically related to schizophrenia. Deficits can be found in other psychiatric syndromes too, especially in manic patients. Generally speaking, the dysfunctions emerge in a milder form in nonschizophrenic patients.

Attention↗