Lexical cohesion and formal thought disorder during and after psychotic episodes

Stability of Thought Disorder Index among high-risk and low-risk adoptees in the Finnish adoptive family study of schizophrenia

The aim of the study was to evaluate whether thought disorders are stable, trait-like features specific to subjects who have a genetic liability to schizophrenia or a psychiatric disorder. The thought disorders of adoptees genetically at high risk (HR) or low risk (LR) for schizophrenia from the Finnish adoptive family study of schizophrenia were evaluated twice at a mean interval of 11 years, using the sum of the Thought Disorder Index (TDI) scores on the Rorschach (TDR). At the initial assessment, the mean TDR scores of women were significantly higher than those of men, while no association between genetic risk and psychiatric status or their interactions with the TDR scores at baseline were found. The main finding was that the initial TDR scores statistically significantly predicted the TDR scores at follow-up, thus indicating the stability of thought disorder over time. However, neither genetic or psychiatric status nor gender or any interaction between these variables associated with TDR at follow-up.

Evidence of disturbances of deep levels of semantic cohesion within personal narratives in schizophrenia

Since initial conceptualizations, schizophrenia has been thought to involve core disturbances in the ability to form complex, integrated ideas. Although this has been studied in terms of formal thought disorder, the level of involvement of altered latent semantic structure is less clear. To explore this question, we compared the personal narratives of adults with schizophrenia (n=200) to those produced by an HIV+ sample (n=55) using selected indices from Coh-Metrix. Coh-Metrix is a software system designed to compute various language usage statistics from transcribed written and spoken language documents. It differs from many other frequency-based systems in that Coh-Metrix measures a wide range of language processes, ranging from basic descriptors (e.g., total words) to indices assessing more sophisticated processes within sentences, between sentences, and across paragraphs (e.g., deep cohesion). Consistent with predictions, the narratives in schizophrenia exhibited less cohesion even after controlling for age and education. Specifically, the schizophrenia group spoke fewer words, demonstrated less connection between ideas and clauses, provided fewer causal/intentional markers, and displayed lower levels of deep cohesion. A classification model using only Coh-Metrix indices found language markers correctly classified participants in nearly three-fourths of cases. These findings suggest a particular pattern of difficulties cohesively connecting thoughts about oneself and the world results in a perceived lack of coherence in schizophrenia. These results are consistent with Bleuler's model of schizophrenia and offer a novel way to understand and measure alterations in thought and speech over time.

The stability of severe thought disorders and mature thinking

The aim of this study was to investigate whether severe formal thought disorders and mature thinking are stable among adoptees (=187) drawn from the Finnish adoptive family study of schizophrenia. A group of 93 adoptees genetically at high risk (HR) and 94 at low risk (LR) for schizophrenia were assessed blindly and reliably using the Index of Primitive Thought (IPT) and the Index of Integration (IOI). Two assessments of the IPT and the IOI were performed with the mean interval of 11 years. Comparisons of the IPT and the IOI mean scores were conducted both at baseline and at follow-up between adoptees at low and high genetic risk, gender, and psychiatric status. The main result was that the IOI as well as the IPT of the adoptees at the initial assessment predicted the IOI and the IPT estimated at follow-up, thus indicating the stability of severe formal thought disorders and mature thinking over time. The stability of IOI or IPT was not related to genetic risk, gender or psychiatric status or their interactions.

Gender differences in speech temporal patterns detected using lagged co-occurrence text-analysis of personal narratives

This paper describes a novel methodology for the detection of speech patterns. Lagged co-occurrence analysis (LCA) utilizes the likelihood that a target word will be uttered in a certain position after a trigger word. Using this methodology, it is possible to uncover a statistically significant repetitive temporal patterns of word use, compared to a random choice of words. To demonstrate this new tool on autobiographical narratives, 200 subjects related each a 5-min story, and these stories were transcribed and subjected to LCA, using software written by the author. This study focuses on establishing the usefulness of LCA in psychological research by examining its associations with gender. The application of LCA to the corpus of personal narratives revealed significant differences in the temporal patterns of using the word "I" between male and female speakers. This finding is particularly demonstrative of the potential for studying speech temporal patterns using LCA, as men and women tend to utter the pronoun "I" in comparable frequencies. Specifically, LCA of the personal narratives showed that, on average, men tended to have shorter interval between their use of the pronoun, while women speak longer between two subsequent utterances of the pronoun. The results of this study are discussed in light of psycholinguistic factors governing male and female speech communities.

Language performance in chronic schizophrenia: a pragmatic approach

In this study, the authors examined the language of 43 participants with chronic schizophrenia under the basic assumption that a paradigmatic shift is needed in the methodology used to investigate the language of schizophrenia. The pragmatic protocol (C. Prutting and D. Kirchner, 1987) was chosen as the method of analysis to attain a general profile of pragmatic abilities. The results showed that the participants with schizophrenia exhibited a high degree of inappropriate pragmatic abilities compared to participants with mixed anxiety-depression disorder and participants with hemispheric brain damage, as previously assessed by Prutting and Kirchner. Statistical methods for clustering analysis yielded 5 distinct parameter clusters: Topic, Speech Acts, Turn-Taking, Lexical, and Nonverbal. Group clustering analysis of the 43 participants with schizophrenia produced 3 distinct groups with different profiles: minimal impairment, lexical impairment, and interactional impairment. The results are discussed in terms of theoretical implications in the area of pragmatics, the diagnosis of schizophrenia, and other goals.

Linguistic analysis of the speech output of schizophrenic, bipolar, and depressive patients

Using speech samples of 100 patients suffering from schizophrenia, bipolar illness and major depression, we addressed the question of the extent to which the linguistic abnormalities in the speech of these patients represent diagnosis-specific characteristics or constitute independent, syndrome-like dimensions of the illnesses. All speech samples were transcribed by a professional linguist who was blind to both identity and diagnosis of the patients. The majority of the deviant linguistic variables was found to be common to all three diagnostic groups under comparison, while only a few linguistic variables exhibited statistically significant between-group differences. On the other hand, when the respective variables were analysed as a multivariate entity, the variety of subtle between-group differences allowed us to discriminate between the diagnostic groups at an overall performance of 72.7% correctly classified patients. There was an almost complete lack of association between linguistic abnormalities and psychopathology syndromes. In particular, we found no correlation between the syndrome 'formal thought disorder' and the large variety of linguistic variables used in this investigation. In consequence, we conjecture that linguistically deviant speech characteristics represent an independent syndrome complex manifested at varying intensities across mental illnesses, and that this syndrome complex deserves greater attention, not only with respect to the principal understanding of the underlying disturbances, but also as a potential target of therapeutical intervention.

The effectiveness of MMPI-A items in discriminating between normative and clinical samples

The Minnesota Multiphasic Personality Inventory-Adolescent (MMPI-A; Butcher et al., 1992) was released in 1992 and has rapidly become the most widely used objective personality assessment instrument with adolescents. Although the MMPI-A reduced or eliminated several problems associated with the use of the original MMPI (Hathaway & McKinley, 1943) with adolescents, the MMPI-A does produce a high frequency of within normal limits basic scale profiles for individuals with substantial psychopathology including adolescents in inpatient psychiatric settings. To better understand the reasons for this phenomenon, we compared the item endorsement frequencies for the MMPI-A normative sample with results from two adolescent clinical samples, and these results were contrasted to the item endorsement frequencies for the MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) normative sample and a clinical sample of adult psychiatric inpatients. Results showed that the MMPI-A contains a substantial number of items that do not show a significant difference in item endorsement frequency between normative and clinical samples. Furthermore, MMPI-A basic and content scales generally show a much lower percentage of effective items than do the corresponding scales for the MMPI-2. We discuss the findings in relation to the frequent occurrence of low range MMPI-A profiles in clinical samples and the potential usefulness of these results in future efforts to develop viable short forms for the MMPI-A.