Philip D. Harvey

Reality Monitoring in Mania and Schizophrenia: The Association of Thought Disorder and Performance

Manic (N = 20) and schizophrenic (N = 20) patients, equally divided into thought-disordered (TD) and non-thought-disordered (NTD) subgroups were compared to a normal contrast sample (N = 10) on their reality-monitoring ability (i.e., recognition of the source of presentation of information in their memory). It was found that TD manics and TD schizophrenics had different problems in reality monitoring, in that TD schizophrenics had problems in differentiating information that they had said from information that they had thought and TD manics had problems in discriminating information presented by two external sources. In addition to their problems in reality monitoring, TD patients in general had a response bias that, was different from that manifested by normal subjects in both the present and earlier investigations. Normals and NTD patients performed similarly throughout, which indicates that there were no correlations of diagnosis and performance in the absence of thought disorder. The results of the present investigation were related to earlier reports of attentional deficits in manics and controlled information-processing deficits in TD schizophrenics. Finally, a tentative model of schizophrenic speech disorder, incorporating the present data with earlier reports of controlled information deficits, was advanced.

The consistency of thought disorder in mania and schizophrenia. An assessment of acute psychotics.

This report presents an assessment of 20 manic and 20 schizophrenic patients using a clinical rating instrument: the Scale for Assessment of Thought, Language, and Communication (TLC). These 40 patients were assessed three times within a 10-day period at the outset of an acute psychotic episode with open-ended interviews which were then evaluated with the TLC. It was found that clinically rated speech disorders were relatively consistent within these patients at the outset of a psychotic episode. Furthermore, it was found that composite ratings of positive and negative speech disorders, as defined by the TLC, were stable discriminators of the manic and schizophrenic patients, while global thought disorder was not useful as a discriminator. The results provide evidence that thought disorder in psychosis may be a stable trait of patients during acute episodes and that positive and negative disorder is a useful construct.

Affective lability versus depression as determinants of binge eating

The relationships between dietary restraint, various affective disturbances, and binge eating were assessed in a sample of 73 college women unselected for bulimia. It was found, replicating earlier results, that the interaction of dietary restraint and depression was a significant predictor of binge eating. However, the interaction of dietary restraint and biphasic mood shifts was an even better predictor of the severity of binge eating and in fact accounted for all of the variance in the relationship of dietary restraint, depression, and binge eating. The results were discussed in terms of the possible role of affective liability in the development of binge eating.

Speech performance in mania and schizophrenia: The association of positive and negative thought disorders and reference failures

The speech performance of manics (n = 21) and schizophrenics (n = 22) was assessed with both clinical evaluations and an assessment of reference performance. The severity of positive and negative clinical thought disorders was correlated with the frequency of incompetent (unclear and ambiguous) references as measured with a linguistic rating system. It was found that pressure of speech accounted for the majority of the variance in incompetent references in the manic sample, while this relationship was not found for the schizophrenics. The number of incompetent references in the schizophrenic sample was most highly predicted by the severity of derailment, with poverty of content of speech the next most important. These results were discussed with respect to their implications for the identification of differential mechanisms underlying speech disorders in the two patient groups.

The prediction of binge eating over time

The stability of dietary restraint and the interrelationships of dietary restraint, depression, and binge eating were assessed over time in a sample of college women (n = 97) unselected for bulimia. Subjects were initially assessed with measures of the three constructs and reassessed at a 5-week interval. It was found that dietary restraint was a stable characteristic in the sample of women. In addition, path analyses indicated that the severity of previous binge eating and the coexistence of high levels of depression and dietary restraint were significant predictors of binge eating over time. Binge eating, however, did not cause high levels of depression and dietary restraint. The results of this investigation were discussed in terms of their implications for the development of binge eating symptomatology.

The consistency of thought disorder in mania and schizophrenia. II. An assessment at consecutive admissions.

Manic (N = 8) and schizophrenic (N = 14) acute admissions were assessed 10 days after they arrived at the hospital. These assessments were conducted on two consecutive acute admissions for each patient. Interview-based clinical ratings were collected and examined for the stability of both positive and negative thought disorders. For schizophrenics, negative thought disorder, particularly poverty of speech, was relatively consistent across admissions. In the manic sample, much less consistency was observed. The results are evaluated in terms of the statements that they make regarding the validity of the thought disorder construct and for their implications regarding causal factors in communication disorders.

Distractibility and discourse failure. Their association in mania and schizophrenia

Manic (N = 18) and schizophrenic (N = 23) patients were evaluated with a linguistic assessment of reference failures and were tested with a digit span distraction task. It was found that, although manics and schizophrenics did not differ in their distraction performance, there were differential relationships between task performance and reference performance across the two subject samples. Both distraction and nondistraction performances were related equally to discourse failures in manics while distraction performance was a much better predictor of discourse failure than nondistraction performance in the schizophrenic sample. The fact that susceptibility to the effects of distraction seemed to be an important and specific predictor of discourse failures in schizophrenia is discussed in terms of recent developments in research and theory regarding schizophrenic speech disorders.

Delusional Thinking in Psychotics: Correlates of Religious Content

Manic (n = 18) and schizophrenic (n = 23) patients were subdivided on the basis of delusional status, with special reference to religious delusions, and compared to a control sample of normal subjects. Assessments of religious attitudes and beliefs, as well as demographic factors, were conducted. No differences existed in the characteristics of manic and schizophrenic patients with delusions, and it was difficult to differentiate delusional patients with and without religious content in their symptoms, although these patients differed in several ways from nondelusional patients and normals. These data are discussed in terms of their implications for theories about the development of delusions.

Linguistic analyses of speech disorder in psychosis

Abstract Much theory and research has been devoted to characterizing speech disorders in psychotic individuals and to understanding the connections between language productions and underlying cognitive processes. Studies in the literature have used primarily traditional clinical assessments and experimental task methods to study speech phenomena in psychotic patients. More recently, however, the range of study methods has expanded to include models based on normal language use, borrowed from the field of psycholinguistics. This article reviews linguistic studies of the discourse of psychotic patients with a focus on understanding speech disorders in the context of schizophrenia and mania. The studies are grouped according to the method of analysis used, including frequency counts, type-token ratios, cloze analyses, contextual constraint, pause and hesitation patterns, and discourse level analyses. Methodological problems and theoretical issues are summarised, followed by a statement of current status. The use of multiple measures applied to whole discourse speech samples offers particular promise for clarifying diagnostic issues and testing hypotheses based on cognitive models.