Biomedical subjects

N M Docherty

Publications and source records attributed to N M Docherty.

At least 19 recordsLinked to original sources

PubMed2001

Factor analysis of the Communication Disturbances Index.

The present study utilized factor analysis to investigate possible underlying processes in schizophrenic thought disorder. Using the Communication Disturbances Index [CDI; Arch. Gen. Psychiatry, 53, (1996) 358], a measure of disruption in the communication of meaning from speaker to listener, we examined the speech of 58 stable schizophrenia outpatients for six different types of referential communication disturbances. We calculated instances of disturbance per 100 words and then factor-analyzed our data using the SAS statistical package. Principal components analysis with an oblique rotation produced both a two- and a three-factor solution, depending on factor inclusion criteria. In the three-factor solution, the first two factors reflected weaknesses in language structural organization and in concept-boundary definition, respectively. The third factor appeared to reflect weaknesses in specific facets of memory functioning. In the two-factor solution, the aforementioned structural organization and concept-boundary definition factors were combined into a single executive functioning factor. Results from the study may be heuristic in the development of models of language disturbance in schizophrenia patients.

Adult↗

PubMed2001

Affective reactivity of language symptoms, startle responding, and inhibition in schizophrenia.

The speech of some schizophrenia patients becomes markedly more disordered when negative affect is aroused. The authors tested associations between affective reactivity of speech and responsiveness and inhibition on an acoustic startle task in a sample of 27 outpatients. Patients whose language was reactive to negative affect showed significantly higher initial startle amplitudes than those whose language was not reactive. However, they also showed greater habituation to repeated startle stimuli over trials, even after differences in initial amplitudes were controlled statistically. These findings suggest that affective reactivity of speech is associated with higher initial startle responsiveness but also with greater habituation and, conversely, that patients who are relatively nonreactive to excitatory affective and sensory stimuli are also less reactive to inhibitory input.

Adult↗

PubMed2000

Conceptual sequencing and disordered speech in schizophrenia.

This study examined associations between impairments of attention, memory, and conceptual sequencing ability, and specific schizophrenia thought and language symptoms. Speech samples of stable schizophrenia outpatients were assessed for frequencies of six different types of communication failures. The classification of types of failures was based on hypothesized differences in underlying cognitive process. Frequencies of the four types of communication failures believed to involve language structural weaknesses all were significantly and fairly strongly related to conceptual sequencing ability. In addition, regression analyses indicated that each of these four types of communication failures was associated with a unique configuration of attentional, memorial, and conceptual sequencing processes. In contrast, the two types of communication disturbances not suggestive of language structural problems were not positively associated with any of the cognitive weaknesses assessed.

Adolescent↗

PubMed2000

A twin study of communication disturbances in schizophrenia.

Relatives of schizophrenia patients have demonstrated several different types of subtle communication disturbances. This study used twin methodology to address the question of whether certain of these disturbances might be reflective of genetic vulnerability. Verbatim interviews from a sample of monozygotic and dizygotic twins in which at least one member of each twin pair had a diagnosis of schizophrenia were rated for three different types of referential communication disturbances. Monozygotic versus dizygotic nonschizophrenic co-twins were compared on each type of disturbance. Associations between the language variables and object sorting test performance also were examined. Differences among subjects in levels of global psychopathology were controlled. Schizophrenic participants showed higher levels of communication disturbance than nonschizophrenic co-twins. One type of communication failure, the "missing information" reference, discriminated monozygotic from dizygotic nonschizophrenic co-twins. This type of failure was associated with specific types of errors on the object sorting test. These findings suggest that missing information references may be an expression of schizophrenia-related genetic vulnerability.

Adult↗

PubMed2000

Parent coping styles and schizophrenic patient behavior as predictors of expressed emotion.

Several studies have examined relationships between levels of expressed emotion in relatives of individuals with schizophrenia and the coping strategies these relatives employ. In an attempt to elucidate these relationships, 44 parents were assessed using the Camberwell Family Interview and the Strategic Approach to Coping Scale. Associations between these measures were examined. Additionally, interactions between parent coping style and patient aggression were assessed with respect to expressed emotion. The results indicate that scores on the coping scale generally were not directly related to levels of expressed emotion. However, an interaction was found between parent coping style and patient behavior which predicted level of expressed emotion. This finding supports the idea that research into the variables underlying expressed emotion should include the assessment of both parent and patient characteristics and examine the interactions between these variables.

Adaptation, Psychological↗

PubMed2000

Perceptual aberration and schizotypy: a cautionary note.

This study assessed 51 college students for associations between Continuous Performance Test performance and schizotypy scale scores. Results suggest that perceptual aberration scores, while generally correlated with overall schizotypy scores, may not be adequate as a single-criterion measure of schizotypy.

Adult↗

PubMed2000

Schizophrenia outpatients' perceptions of their parents: is expressed emotion a factor?

The factors that mediate the association between expressed emotion (EE) and relapse in schizophrenia patients are still unknown. Many researchers hypothesize that interactions with high-EE individuals are stressful for patients, leaving them vulnerable to relapse. It would be useful to investigate whether patients perceive interactions with high-EE parents as stressful. In this study, associations were examined between levels of EE in parents and the types of personal memories patients had about these parents. EE ratings were obtained for both parents of 27 schizophrenia outpatients, and patients were asked to describe "happy, nonstressful" memories and "unhappy, stressful" memories during 2 interviews. Patients recounted fewer nonstressful memories and more stressful memories about high-versus low-EE parents. Implications of these results are discussed.

Adult↗

PubMed1999

Immediate memory, attention and communication disturbances in schizophrenia patients and their relatives.

BACKGROUND: Schizophrenia has been defined in part by disturbances of thought and language. The non-schizophrenic relatives of patients also have been found to show subtle disturbances of language that may be associated with vulnerability. Investigators have hypothesized that these phenomena in patients and their relatives are, at least in part, the result of weaknesses in facets of attention and memory. METHODS: The present study assessed some neuropsychological process correlates of three different measures of thought and language symptoms in 55 stable out-patients, using tests of immediate auditory memory impairment and auditory distractability, and carefully controlling for generalized deficit effects. A parallel assessment was made of referential communication disturbances in 59 non-schizophrenic relatives of patients and 24 control subjects matched to the relatives. RESULTS: In patients, formal thought disorder, disorganization, and referential communication disturbances were all associated with each other and with auditory distractability. In addition, as expected, referential communication disturbances were associated with immediate auditory memory impairment. Referential disturbance ratings for relatives were similar in magnitude to those for the stable out-patients, and much higher than for controls. However, the relatives' language ratings were not associated specifically with weaknesses in attention or memory as measured. CONCLUSIONS: Impairments in immediate auditory memory and attention are associated differentially with different types of communication disturbances in schizophrenia patients. The cognitive substrate for referential communication disturbances in relatives appears to differ qualitatively from that for patients.

Adult↗

PubMed1999

Communication disturbances in relatives beyond the age of risk for schizophrenia and their associations with symptoms in patients.

This article provides a detailed examination of subclinical disturbances in the natural speech of healthy relatives beyond the age of risk for schizophrenia. Speech samples from 43 stable schizophrenia outpatients, 42 nonschizophrenia parents of patients (pairs only), and 23 control subjects matched to the parents were analyzed for frequencies of six specific types of communication failures. The parents had higher overall communication disturbance ratings than the control subjects. The specific types of failures that occurred more frequently were unclarities caused by (1) language structural breakdown, (2) use of vague, overinclusive words, and (3) use of words with ambiguous meanings. In intrafamilial analyses, higher levels of communication disturbance in parents were associated with greater severity of illness in their patient offspring. These results support the idea that communication disturbances may be one manifestation of a stable genetic vulnerability to schizophrenia. The nature of the failures identified suggests the possible involvement of weaknesses in specific areas of cognitive functioning.

Adult↗

PubMed1998

Affective reactivity of speech in schizophrenia patients and their nonschizophrenic relatives.

This study compared levels of referential communication disturbance in speech samples from 41 stable schizophrenia outpatients, 46 parents of patients, and 23 nonpsychiatric control participants in affectively positive versus affectively negative conditions. The speech of the patients and parents showed elevated frequencies of reference failures in the affectively positive condition compared with control participants: the speech of the patients became more disordered in the affectively negative condition, whereas the speech of the parents did not. These results support the idea that referential communication disturbances reflect vulnerability, as well as overt illness, but that affective reactivity of these disturbances is associated mainly with the manifest illness. These findings are consistent with biological, cognitive, and psychological theories about the processes underlying stress responsiveness of schizophrenic symptoms more generally.

Adult↗

PubMed1998

Expressed emotion and differentiation of self in the relatives of stable schizophrenia outpatients.

This study examined "trait" variables associated with high and low levels of expressed emotion in the parents of long-term stable schizophrenia outpatients. Self-descriptions collected from patients, their parents, and control participants matched to the parents were rated for levels of differentiation and integration, substantiality, relatedness, and self-criticism using established methods. The parents as a group did not differ from controls on any of the self-description variables. When parents were classified based on their expressed emotion status, those with low expressed emotion showed higher levels of differentiation and integration than those with high expressed emotion. Low expressed emotion parents were also lower on self-criticism. There was no difference between expressed emotion groups on substantiality or relatedness. These findings support the idea that high expressed emotion in parents of long-term stable outpatients may be a manifestation in part of relatively low levels of differentiation and integration of self in the parents. Furthermore, though patients as a group scored lower than parents on differentiation and integration and substantiality, patients' ratings on these two variables also correlated with those of their parents, suggesting that these variables are to some extent familially determined.

Adult↗

PubMed1998

Communication disturbances and family psychiatric history in parents of schizophrenic patients.

Parents of schizophrenic patients have demonstrated subtle disturbances of thought, language, and communication. The etiologic relevance of these disturbances is not clear. This study assessed levels of referential communication disturbance in the "natural speech" of schizophrenic patients, nonschizophrenic parents of patients, and control subjects matched to the patients' parents and tested for associations of communication disturbances in parents with family history of psychosis and with schizotypy scale scores. The speech of the patients' parents as a group contained high frequencies of referential failures. Those parents with first-degree family histories of psychosis and/or high schizotypy scale scores made more frequent referential failures than the rest of the parents. Family history was particularly highly associated with failures involving language structural breakdown. The results of this study suggest that referential disturbances in parents of patients may be related to genetic liability in the parents. However, such an effect does not appear to account fully for the sizable differences between parents and controls in levels of communication disturbance.

Adult↗

PubMed1997

Comparative affective reactivity of different types of communication disturbances in schizophrenia.

Twenty-nine schizophrenic outpatients provided speech samples on affectively positive and negative topics. These samples were assessed for several different types of communication failures by using the Communication Disturbances Index. Frequencies of overinclusive references, ambiguous word meanings, and ambiguous referents increased in the affectively negative condition; frequencies of missing referents and instances of syntactic unclarity did not change across affective conditions. Degree of overall affective reactivity of speech was associated with severity of the core positive schizophrenic syndrome. These findings support the idea that different types of schizophrenic communication disturbances are associated with different underlying pathophysiological processes, that some are more reactive to affect than others, and that affective reactivity of these symptoms is associated with the positive schizophrenic process.

Adult↗

PubMed1997

Communication disturbances in the natural speech of schizophrenic patients and non-schizophrenic parents of patients.

Subclinical communication disturbances in the relatives of schizophrenic patients appear to be heterogeneous in both form and origin. The Communication Disturbances Index (CDI) was applied to the natural speech of stable schizophrenic out patients, non-schizophrenic parents of patients, and control subjects. The parents of schizophrenic patients displayed more frequent overall instances of communication failure in their speech than the controls. The specific types of disturbance that were more frequent were structural lack of clarity, vague references and ambiguous word meanings. The parents did not differ significantly from the patients with regard to total CDI ratings. However, patients made more frequent missing-information references than parents, and parents made more frequent vague references than patients. High CDI scores in parents were associated with more severe lifetime core positive symptoms in their patient offspring.

Adult↗

PubMed1997

Cognition, negative symptoms, and diagnosis: a comparison of schizophrenic, bipolar, and control samples.

Forty-six schizophrenic, 22 bipolar, and 26 normal control subjects were administered negative and positive symptoms scales and tests of cognitive function. Test performance was related to diagnosis and to positive and negative symptom ratings within the schizophrenic group. Bipolar patients were significantly superior in cognitive status when compared with all schizophrenic patients, but less so when compared only with those who did not have key negative symptoms (affective nonresponsivity and poverty of speech). The schizophrenic patients with negative symptoms displayed severe impairment, performing significantly worse than the control, bipolar, and other schizophrenic subjects. Negative symptoms thus are significantly implicated in the cognitive inferiority of schizophrenic to bipolar patients. Although the data suggest bipolar patients may also have cognitive deficiencies, these findings are inconclusive and require cross-validation.

Adult↗

PubMed1996

Affective reactivity of cognitive functioning and family history in schizophrenia.

This article reports the results of two related studies investigating the association between affective reactivity of cognitive functioning in schizophrenia and family psychiatric history. In Study #1, we examined affective reactivity of positive formal thought disorder symptoms in 29 schizophrenic inpatients. We found that thought disorder was greatly exacerbated by negative affect in those patients with a family history of schizophrenia (SFH) (n = 11), and not in those without the family history (SNFH) (n = 18). In Study #2, we replicated this finding with a stable outpatient sample (n = 10). We also administered dichotic listening tests using affectively neutral and affectively negative stimuli, and found that right-ear advantage was more markedly diminished on the affectively negative task than on the neutral task in the SFH (n = 6) but not the SNFH (n = 4) subjects. These findings support our hypothesis that cognitive symptoms in schizophrenia are exacerbated by negative affect, and that this affective reactivity of symptoms is associated with a familial form of the disorder.

Adult↗

PubMed1996

Communication disturbances in schizophrenia and mania.

BACKGROUND: A "natural language" measure was developed for classifying type and severity of communication disturbance in the speech of psychotic patients by assessing their linguistic reference performance. METHODS: This measure was applied to speech samples of schizophrenic, manic, and nonpsychiatric subjects, and the groups were compared on levels and types of communication failures. RESULTS: The speech of the schizophrenic and manic subjects contained much higher frequencies of each of six types of communication failures than did the speech of the control subjects. Proportions of the different types of unclarity differed among the diagnostic groups. CONCLUSIONS: This method provides a measure of overall severity of communication disturbance, discriminates the speech of schizophrenic and manic subjects from that of nonpsychiatric subjects, and reflects some differences in distribution of types of communication failure in schizophrenic vs manic patients. The measure may be helpful in elucidating cognitive weaknesses underlying psychotic communication failures.

Adult↗

PubMed1996

Working memory, attention, and communication disturbances in schizophrenia.

The authors hypothesized that schizophrenic communication disturbances reflect specific cognitive deficits in the areas of working memory and attention. They examined the cognitive correlates of communication disturbances, as measured by linguistic reference performance, in schizophrenic (n = 48), bipolar (n = 24), and nonpsychiatric control (n = 23) individuals. Reference performance ratings in the schizophrenic patients were associated with scores on tests of working memory and attention and were not related to performance on concept formation or verbal fluency tests. In contrast, in the bipolar and nonpsychiatric individuals, reference performance was associated with concept formation and verbal fluency test scores but was not related to performance on tests of working memory. Implications with respect to the processes underlying schizophrenic communication disturbances are discussed.

Adult↗